-Sercel_428XL_manuals_-_en428user1

Ref. No. 0311430 April 20, 2006

428XLV1.0

User’s ManualVol. 1

To contact SERCEL

EuropeNantes, FranceSales; Customer Support;Manufacturing & Repair.B.P. 30439, 16 rue de Bel Air44474 Carquefou CedexTel: +33 2 40 30 11 81, Fax: +33 2 40 30 19 48Hot-Line: Land: +33 2 40 30 58 88

Marine: +33 2 40 30 59 59E-mail: [email protected]

[email protected] Gaudens, FranceVibrator Customer Support;Vibrator Manufacturing & Repair;Streamer Manufacturing & Repair.Tel: +33 5 61 89 90 00, Fax: +33 5 61 89 90 45Hot Line: +33 5 61 89 90 91

Les Ulis, FranceSales; Customer SupportTel: +33 1 69 93 83 60, Fax: +33 1 69 81 78 09E-mail: [email protected], FranceSales; Customer SupportTel: +33 2 98 05 29 05; Fax: +33 2 98 05 52 41E-mail: [email protected]

Toulon, FranceSales; Customer SupportTel: +33 4 94 21 69 92; Fax: +33 4 94 21 73 44E-mail: [email protected], U. K.Streamer Manufacturing & Repair;Customer Support.Tel: +44 1 773 605 078, Fax: +44 1 773 541 778E-mail: [email protected]

[email protected]

RussiaMoscow, RussiaSales; Customer Support.Tel: +7 095 254 06 59, Fax: +7 095 254 66 80E-mail: [email protected]

Surgut, RussiaCustomer SupportTel / Fax: +7 3462 28 92 50E-mail: [email protected]

North AmericaHouston, USASales; Customer SupportManufacturing & Repair;Tel: +1 281 492 66 88, Fax: +1 281 579 75 05Hot-Line: +1 281 492 66 88E-mail: [email protected]

[email protected]@sercelus.com

CalgarySales; Customer Support; Manufacturing Tel: +1 403 275 3544, Fax: +1 403 295 1805E-mail: [email protected]

Middle EastDubai, U. A. E.Customer Support.Tel: +971 4 8832142, Fax: +971 4 8832143Hot Line: +971 50 6451752E-mail: [email protected]

Far EastBeijing, P. R. of China Sales; Customer Support.Tel: +86 106 43 76 661, Fax: +86 106 43 76 367Xian, P. R. of ChinaManufacturing & Repair.Tel / Fax: +86 29 8222 9504

Xushui, P. R. of ChinaManufacturing & Repair.Tel:+86.312.8648355, Fax:+86.312.8648441SingaporeStreamer Manufacturing & Repair;Customer Support.Tel:+65 6 545 0411, Fax:+65 6 545 1418

AustraliaStreamer Manufacturing & RepairOBC EquipmentTel:+61 2 8832 5500, Fax:+61 2 8832 5555

AsiaDehradun, IndiaCustomer Support.Tel: +91 135 2761 078 / 2763 387,Fax: +91 135 2763 133E-mail: [email protected]

April 20, 2006 3

428XL User’s Manual Vol. 1

In no event shall SERCEL be liable for incidental or consequential damages or related expenses resulting from the use of this product, or arising out of or related to this manual or the information contained in it, even if SERCEL has been advised, or knew or should have known of the possibility of such damages.The information included in this documentation is believed to be accurate and reliable. However, SERCEL reserves the right to make changes to its products or specifications at any time, without notice, in order to improve design or performance and to supply the best possible product. This documentation does not form in any way a contractual agreement of sales promise on the part of SERCEL.Software mentioned in this documentation is sold under a precise licence agreement and as such the documentation may cover technical areas for which the user may not have a final licence.No part of this documentation, or any of the information included herein may be modified or copied in any form or by any means without the prior written consent of SERCEL.

© 2005 Sercel. All Rights Reserved.Printed in France.

Sercel, 428XL, 428XLS, AIB, DPG, DSD, DSU1, DSU3, e-428, eSQC Pro, FDPA428, FDU, FDU-428, HSU, LandPro Bin, LAUL, LAUL-428, LAULS, LAUX, LAUX-428, LAUXS, Link, LL428, LLIU, LRU, LSI, LSS, LT428, LX, MGA, MRU, MSI, QT428, SGA, TMS428, TMU428, VE432, VQC88, WPSR are all trademarks of Sercel. All rights reserved.

UNIX is either a registered trademark or trademark of The Open Group in the United States and/or other countries.Microsoft and Windows are either registered trademarks or trademarks of Microsoft Corporation in the United States and/or other countries. Other product and company names mentioned herein may be the trademarks of their respective owners.

April 20, 2006 4

428XL User’s Manual Vol. 1

Revision history

Date of revision

Chapters or pages

affected Description of revision or reason for change

Nov. 2005 V 1.0 release

Contentsof

Table

Revision history . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .4

1 Getting startedOverview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .14Starting/stopping the 428XL server . . . . . . . . . . . . . . . . . . . . . . . . .16Opening a user session . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .17Hands-on guide. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .22Server Administration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29

Registering a new user . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .29Session manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .31Licence information . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .32System scaling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .33

2 Installation setupOverview. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .38The 428XL Install window. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .39

Seismic recording instrumentation . . . . . . . . . . . . . . . . . . . . . .39Peripherals . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .42Mobile Receiver Unit (MRU) . . . . . . . . . . . . . . . . . . . . . . . . . .44Export mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .45

428XL User’s Manual Vol. 1 5April 20, 2006

Table of Contents

3 ConfigurationThe main window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48

Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .48Customer Support . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49Copyrights . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .49Identity Card . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .50

The Setup menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52Crew setup window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .52User Info setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .55SEGD setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .56Disk Record setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .57

On Line/Off Line . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .58

4 LineThe main window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .62Topographic views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64

About topographic views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .64Sensor view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .66Instrument view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .68Battery view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .70Seismonitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .71Working with graphic views . . . . . . . . . . . . . . . . . . . . . . . . . . .72

Numeric views . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .77The Survey setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .79Survey . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .80Point Code . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .82Sensor type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .83

The Layout setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .86

6 428XL User’s Manual Vol. 1April 20, 2006

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Markers . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .87Auxiliary channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .90Detour . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .92Mute channels . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .94

The Spread Type setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .95Absolute spreads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .96Generic spreads . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .97

The Look setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .100LAU Leakage setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .101Advanced layouts . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .103

Detour with skipped receiver points . . . . . . . . . . . . . . . . . . . .103Snaking layout . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .104Logical line mapped with several physical lines . . . . . . . . . . .105

Test functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .107Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .107Instrument tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .110Sensor tests . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .112Seismonitor . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .115

The Form Line setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .116Line Troubleshooting . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .117Network Management . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .119

The Synthetic setup. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .121The Download setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .126

5 OperationThe Main Window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .132

General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .132The Operation Table . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .133


Table of Contents

The Active Source view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .135The Active Acquisition view . . . . . . . . . . . . . . . . . . . . . . . . . .138

The Process Type setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .139General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .139Auxiliary traces . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .144Impulsive type . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .146Impulsive Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .147Correlation Before Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . .148Correlation After Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .149Vibroseismic Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .151How to Generate a Process Type . . . . . . . . . . . . . . . . . . . . . . .152

The Source Point Setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .154Source point parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .154To generate a Source Point setup . . . . . . . . . . . . . . . . . . . . . .156

The Seismic setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .158Operating Mode . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .158Automation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .159Look . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .160

The Source Type setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .162Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .162Explosive source parameters . . . . . . . . . . . . . . . . . . . . . . . . . .163Vibroseismic source parameters . . . . . . . . . . . . . . . . . . . . . . .164

The Delay setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .168The Noise Editing setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .169

Noise editing parameters . . . . . . . . . . . . . . . . . . . . . . . . . . . . .169Noise editing thresholds . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .173

The Observer’s Comment Type Setup . . . . . . . . . . . . . . . . . . . . . .175How to take shots or sweeps. . . . . . . . . . . . . . . . . . . . . . . . . . . . . .176

Blaster shots . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .176


Table of Contents

VE432 sweeps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .177Flip-Flop sweeps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .179Slip-sweep . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .184

More About Noise Elimination . . . . . . . . . . . . . . . . . . . . . . . . . . .192“Spike Editing” method . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .192Diversity Stack . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .195

More About Correlation . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .198Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .198Data Distribution . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .201

6 PositioningThe main window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .206The Setup menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .209

The Datum Type setup window . . . . . . . . . . . . . . . . . . . . . . . .209The Projection Type setup window . . . . . . . . . . . . . . . . . . . . .211Quality Warning setup window . . . . . . . . . . . . . . . . . . . . . . . .213The Vehicle Identity setup . . . . . . . . . . . . . . . . . . . . . . . . . . . .216

The geographical view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .218General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .218The layer manager . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .222Background . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .223GeoZones . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .225Swath . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .226Miscellaneous . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .228Vehicles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .229Sources . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .229

The Tracking view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .231Graphical tracking view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .231Numerical tracking view . . . . . . . . . . . . . . . . . . . . . . . . . . . . .234More about the estimated COG position . . . . . . . . . . . . . . . . .234


Table of Contents

Vehicles . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .236Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .236Supported vehicle tracking systems . . . . . . . . . . . . . . . . . . . . .237Customizing tracked vehicles . . . . . . . . . . . . . . . . . . . . . . . . .239Vehicle trackline and history file . . . . . . . . . . . . . . . . . . . . . . .240

The Alert system. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .241Emergency . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .241GeoZone perimeter . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .242Global alarms . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .243Excess speed . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .245

Working with the GIS. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .247Object labelling . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .247Attribute colour maps . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .248Query builder . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .250

Basic Geodesy Glossary . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .252

7 ExportThe main window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .254The Setup menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .255

The Tape Setup setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .255The FTP setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .257The NFS setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .258

The Functions menu . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .259Auto . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .259Tape . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .260

Reading exported files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .262

8 VE432The main window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .264The Vibrator Crew setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .266


Table of Contents

The Basic Type setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .269Overview . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .269Linear . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .271dB/Hz Log, Tn and dB/Octave Log . . . . . . . . . . . . . . . . . . . . .272Pulse . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .277Random . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .278Custom . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .279Compound . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .281Delay . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .282Deboost option . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .282Generating a Basic Type setup . . . . . . . . . . . . . . . . . . . . . . . .284

The Acquisition Type setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .285The Radio Management setup . . . . . . . . . . . . . . . . . . . . . . . . . . . .288The QC Limit setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .291The QC Choice setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .292The T0 Time setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .293Functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .295

Auto/Manual . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .295Look . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .296Vibrator Fleet . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .298Local Acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .299Set DSD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .301Get DSD . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .302Radio functions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .305Set Servo . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .310Statistics . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .313

Normal acquisition . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .315General . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .315Graphic view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .316Numeric view . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .319


Table of Contents

DPG/DSD status codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .321

9 LogThe main window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .324Editing/saving/loading 428XL parameters . . . . . . . . . . . . . . . . . . .327SPS files . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .329

The SPS format . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .329Importing an SPS file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .330Exporting an SPS file . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .332

The Shooting setup window . . . . . . . . . . . . . . . . . . . . . . . . . . . . .333Operator reports . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .336

Observer Logs . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .336APS . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .337APS Verbose . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .338Source COG . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .338Receiver position history data . . . . . . . . . . . . . . . . . . . . . . . . .338VE432 QC . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .339

10 PlotterThe main window . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .342The Banner setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .345Selecting the traces to plot . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .351Plot parameters for production shots . . . . . . . . . . . . . . . . . . . . . . .354

Processing setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .354Rendering setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .358Format setup . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .358

Test records. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .361


Chapter

1 Getting started

This chapter is intended for beginners. It briefly teaches a local or remote user how to get started. Also, this chapter describes how to use the crew’s Server Administration window and Web site. It includes the following sections:

• Overview (page 14)

• Starting/stopping the 428XL server (page 16)

• Opening a user session (page 17)

• Hands-on guide (page 22)

• Server Administration (page 29)


Getting startedOverview

1

OverviewThe documentation coming with the 428XL system consists of the following manuals:

• Installation Manual (0311428): contains an introduction to the 428XL system, installation information, a few instructions for the operator to get started, and reference information that will help you select a 428XL configuration tailored to your needs.

• User’s Manual Volume 1 (0311430): this manual, describing the parameters displayed on the system’s Graphic User Interface and how to use each window.

• User’s Manual Volume 2 (0311431): contains information on logged data and on interfaces (description of Input/Output formats, including the SEGD format).

• User’s Manual Volume 3 (0311432): contains reference information (filter charts, theory of tests, technical data, release notes, specifications).

• Technical Manual (0311429): contains maintenance and repair information, including operating instructions for using the system’s testers.

Before using this manual, you need to install the system by following the instructions given in the 428XL Installation Manual.

The User’s Manual is automatically loaded from the 428XL CDROM to your workstation’s disk as you load the 428XL software package. Then it is just one click away at all times, using the Help button available in every main window. With a PC computer equipped with a PDF file reader (Adobe Acrobat Reader) you can view this manual direct from the 428XL CDROM’s DOC directory.

This manual assumes you are familiar with window-driven systems and you know how to work with windows, including how to use a mouse and standard menus and commands, and to open, move, resize, shrink, restore and close a window.


Getting startedOverview

1
To start the server, if required, see Starting/stopping the 428XL server on page 16
To launch the 428XL Graphic User Interface, see Opening a user session (page 17).


Getting startedStarting/stopping the 428XL server

1

Starting/stopping the 428XL serverThe 428XL server is started automatically when you power up the server workstation.

If you need to start, stop or restart the server, do the following:

• To start the server, do the following:

- Log in with the User name used for the 428XL.

- Type r in a Terminal window.

• To stop the server, type s in a Terminal window.


Getting startedOpening a user session

1
Opening a user sessionTo open a user session:
- Double-click on the 428XL Client icon on your desktop.

- Wait until the launcher bar appears.

All icons in the launcher bar (except the connection icon and the Help button) are dimmed until you get connected.

Right-clicking on the “Connection” icon causes a menu to pop up, prompting the following commands:

• Connection: used for Connection (page 18) to the server.

• Look&Feel: used to change the look of the GUI.

• JAdmin: used for Server Administration (page 29).

• Exit: used to close the 428XL Client application.

• Settings: see Application Settings below.

Application Settings

Figure 1-2

Browser settingsAllows you to choose which Web Browser to use. The browser used by default is Internet Explorer on a PC under Windows. If you wish to use

Figure 1-1



1

a different browser, specify its location in the path field and address in the URL field.

Regional settingsAllows you to choose the Help language (English/Chinese/Russian/Spanish).

ConnectionThis command is selected by default on a left-click. It opens a connection window:

Figure 1-3

Advanced ParametersIf your machine uses a Proxy server, click on the Advanced Parameters tab to set the Proxy configuration.

Choose “Enabled”, then enter the same configuration (Host name and Port) as in your Web browser (see the Internet connection options in your browser).

Click here to connect

Figure 1-4



1
Remote ServerTo connect to the server, click on the Remote Server tab, then do the following:
Figure 1-5

1. Choose the type of connection: “Local user” if you are opening a user session on the server workstation itself or your PC is attached to the crew’s local network (172.27.128.x), “Remote user” otherwise.

2. The Label field is used to enter a name for your connection profile. Choose a name that will clearly identify your connection profile (e. g. your name plus the product’s name).

3. In the URL field, type the desired crew address, for example:

- localhost if you are connecting as “Local user” on the server workstation itself, or 172.27.128.1 if you are connecting as an extra “Local user”.

- http://nnn.nnn.nnn.nnn if you are connecting as an Intranet or Internet “Remote user”, nnn.nnn.nnn.nnn being the IP address of the nearest Seismic Gateway (depending on which Seismic Gateway computer is visible to your computer). If you know the machine name, you can use it in place of the IP address.

4. In the Login and Password fields, type your Login name and password respectively (supplied to you by the Senior Observer).

1

23

4

5



1

5. Click Connect. The 428XL launcher bar should show up on your desktop (see Figure 1-6).

• The Installation icon is used to set installation parameters for the server workstation (licences, number of cards in the Control Module, attached peripherals, source controllers, etc.). See Installation setup on page 37.

• The Configuration icon is used to set the crew’s basic parameters, provide information on the hardware and software configuration of the system, specify how your SEGD files must be recorded, and enable/disable communications with the Control Module. See Configuration on page 47.

• The Line icon is used for the management of the field electronics. See Line on page 61

• The Operation icon is used for the management of shots. See Operation on page 131.

• The Export icon is used for the management of your recording media. See Export on page 253.

• The Positioning icon is used for viewing source points, tracking vehicles, etc. See Positioning on page 205.

• The VE432 icon opens the Graphic User Interface for the VE432 vibrator controller. See VE432 on page 263.

• The Log icon is used to save/load setup parameters, import/export processing support (SPS) files, export operator reports, and for the management of all reports. See Log on page 323.

• The Plotter icon is used for monitoring traces on a plotter. See Plotter on page 341.

Figure 1-6 Launcher bar

VE432

Installation

Configuration

Line

Operation

Export

Positioning

Log

Plotter

Website

Help

Server Power Off (Observer only)



1
• The Website allows you to download or upload SPS files, report files,
etc.

• The Help icon displays help information relating to Client windows only.

• The Power Off button (used for shutting down the server workstation) is only available to a user with Observer or Senior Observer role privileges.

In addition, an Administration window is available (by right-clicking on the connection icon in the launcher bar and selecting JAdmin from the menu that pops up), intended for a user with Observer or Senior Observer role privileges to register users, manage passwords and sessions, etc. See Server Administration (page 29).


Getting startedHands-on guide

1

Hands-on guideThis hands-on guide teaches a beginner how to customize a main window (also referred to as “client window”) in just a few clicks. The first time you log on to a 428XL server, each main window in the Graphic User Interface is configured with a default layout. Then, your customized window layout is automatically saved on your computer as you close the client window, and recovered when you next open it.

In most main windows, it is for you to decide how many views to show and where to place them. The GUI may also let you decide which information to view, and which type (numerical/graphical) of view you want for this information. The intent of the procedure below is to give you a glimpse of what you can do to customize each main window, using the “Line” window as an example.

1. Open the Line main window (click on the Line icon in the 428XL launcher bar).

2. On the right-hand border of each toolbar is a down arrow button. Clicking on that button causes a menu to pop up for you to choose which buttons you would like to show or hide in the toolbar. (All options are also available from the menu bar).

Figure 1-7 Customizing toolbars

3. Clicking on the left-hand (shaded) border of the toolbar and holding down the mouse button allows you to move and dock the

(2) Click to customize toolbars

(3) Move to dock elsewhere or to undock

Undocked toolbar

(4) More options (click to choose)

Menu bar



1
toolbar to whichever border you like inside the window. Moving it outside the window will undock the toolbar (to dock it again, simply close it by clicking on the button in the upper right corner of the undocked toolbar).
4. A double-arrow button (>>) appears if more options are available but the toolbar is too small for all buttons to fit in. Clicking on that button causes the hidden options to pop up for you to choose whichever you like.

Figure 1-8 Window resizing

5. The arrow buttons in the corners of a display pane let you expand or collapse the pane vertically or horizontally.

6. Adjust the width of each display pane by dragging the vertical border to the left/right. Likewise, to adjust its height by dragging the horizontal border upward/downward.

7. To show the different views available, use either the View menu or toolbar buttons. When you choose to add a view, the new view pane appears below the currently selected pane.

(5) Expand/collapse vertically

(6) Drag border to adjust height

(6) Drag border to adjust width

(5) Expand/collapse horizontally



1

Figure 1-9 Adding view panes

8. To hide any view pane, click on the close button associated with its tab.

9. If the pane is not large enough for the whole view to fit in, you can resize the main window and/or use the available scrollbars.

Figure 1-10 Customizing view panes

In graphical views, you can zoom in by pressing the left mouse button, moving the mouse, then releasing the button. Use the zoom control buttons to zoom out or go back to the whole view.

10. Double-clicking on the tab of any view pane either expands or collapses the view.

(10) Double-click on tab to expand/collapse view

(9) Horizontal scrollbar

(9) Vertical scrollbar

View all(11 Drag tab to move view

(8) Click to hide view

Zoom out



1
11. You can customize the layout of the main window by placing the
different views where you like them: with the mouse pointer resting on the tab of any view pane, press the left mouse button, then move the mouse so as to drag the tab to where you would like the view pane to appear.

Placing tabs side by side will cause the view panes to be cascaded. Where views are cascaded, you bring any view to the front by simply clicking on its tab.

Figure 1-11 Moving view tabs

Also, view panes can be tiled vertically and/or horizontally. With the example shown in Figure 1-11, dragging the tab to (A) will split the window vertically and place the view into the left-hand pane. Dragging the tab to (B) will split the window horizontally and place the view into the bottom pane. Dragging the tab to (C) will split the window vertically and place the view into the right-hand pane (see Figure 1-12).

A

B

C

Cascaded views



1

Figure 1-12 Tiled views

12. Double-clicking on the button in the lower right corner or each main window enables or disables the automatic updating of the window. That button is green if automatic updating is enabled, red otherwise. The automatic update option is also available from the the Preferences Setup menu, which allows you to adjust the refresh rate. The blinking of the heartbeat-like indicator at the foot of the window is indicative of the window being refreshed.

Figure 1-13 Preference setup

13. 428XL messages appear in the “Status Mail” pane at the foot of the main window. Whether you choose to show or hide that pane, the orientation of the Mail icon in the toolbar will tell you if any

(12) Enable/disable Automatic Update



1
message is present (the mail icon being raised is indicative of one or more messages being present). To delete mail messages, right-click in the Status Mail pane and select “Clear Status” from the menu that pops up.
14. Most tables in numeric views can be customized by right-clicking on any column heading and selecting “Customize” from the menu that pops up.

Figure 1-14 Customizing tables

15. Any heading appearing in bold style in the Displayed columns list means that you cannot remove that column (but you can move it using the up or down arrow button).

16. Any heading appearing in bold style and underlined means you can neither remove nor move the column (it is always entirely visible and at the same position in the table). All other columns can be moved or removed.

17. Click in either list box to choose which column to show or hide, then use the double-arrow buttons to move it to the other list box.

18. Use the up or down arrow button to place each column where you would like it to appear in the table.

(14) Right-click on column heading

(15) Bold means it cannot be removed

(16) Bold and underlined (neither removed nor moved)

(18) Use to rearrange

(17) Click to hide selected column



1

19. You can save that table configuration by clicking on Save and entering a name for it in the dialog box that shows up. Subsequently, you’ll simply have to select the desired type of table from the “Select a Preset” option button and click Apply to recover your preferred arrangement of columns at your convenience.

20. You can also change the order of columns by clicking on a column heading in the table, then dragging and dropping it where you would like it to appear (unless you are not allowed to move that column).

Figure 1-15

21. To resize a column, simply drag its border to the desired width. Some columns, however, have a minimum width that you are not allowed to override.

22. Clicking on a column heading may cause an up or down arrow to appear in that heading, allowing you to scroll through the table if more rows can be viewed.

(20) Drag and drop column heading

(21) Drag border to resize


Getting startedServer Administration

1
Server AdministrationIn this section:
• Registering a new user (page 29)

• Session manager (page 31)

• Licence information (page 32)

• System scaling (page 33)

Registering a new user A new user cannot log on to a crew’s server unless and until he is registered on that server. Only a user with Senior Observer role privileges is allowed to register a remote user.

To register a new user, do the following:

1. Open the Administration window (right-click on the connection icon in the launcher bar and select JAdmin).

Figure 1-16 Administration window

2. Click on the Users tab. Right-click in the list of profiles and select New from the menu that pops up.

Right-click

Appears only if you log on with Senior Observer role

privileges



1

- In the “Name” and “Password” fields, enter the login name and password you wish to create for the new user.

- Click OK. As a result, the new user appears in the list of authorized users.

- Choose the desired Password Expiry Date option (either choose Never or enter the desired expiry date). The Expiry Date takes effect at 12 a.m. (server local time).

- From the Role button, choose the privileges you wish to grant to that user (Guest, or Observer, or Senior Observer permissions).

- Click Apply.

3. Notify the user of the Login name and Password you have created.

Note: After a profile is created, you can change or delete it by right-clicking on it in the list of profiles and using the menu that pops up.

Role Permissions

Guest

• Opening any client window and:- Viewing the crew’s parameter settings

(changes are of no effect),- Viewing results, generating reports;

• Website access.

Observer

All “Guest” role privileges plus the following:• Changing the crew’s parameter settings.• Session administration.• Changing the installation parameters.

Senior ObserverAll “Observer” role privileges plus the following:• User administration.

Figure 1-17



1
Session manager
Open the Administration window (right-click on the connection icon in the launcher bar and select JAdmin), then click on the Sessions tab. This displays a session manager view with a navigation pane showing all opened sessions.

Unless you are logged on to the crew’s server with Observer or Senior Observer role privileges, you are not allowed to make any changes in the session manager window.

Figure 1-18 Session manager

Clicking on any session causes detailed information to be displayed below the navigation pane.

Right-clicking on any session causes a contextual menu to pop up, prompting the necessary commands for the management of sessions:

To close a session, right-click on it and select “Kill”.

Click on session to show details

Right-click

Details



1

Licence informationOpen the Administration window (right-click on the connection icon in the launcher bar and select JAdmin), then click on the Licences tab. This displays information that is not displayed in the Install window when you enter your licence code (Expiry date, allowed tokens, etc.).

Figure 1-19

Note A message will appear in the Terminal window of the server workstation 24 hours before your software licence expires, but it is advisable to use the Administration window to check the expiry date before that.



1
System scaling
Selecting Scaling Common or Scaling PRM from the Setup menu opens a window that allows you to change default settings in your system in order to best suit your crew’s requirements.

Figure 1-20 Common scaling parameters

• Max ext dev msg len: (1024 by default).

• Maximum Nb of LAU: ( by default).

• Maximum Nb of LRU: ( by default).

• Maximum Nb of LAUR: ( by default).

• Maximum nb of traces: (4000 by default).

• Maximum open VP: (2 by default, 4 max.). Up to four Vibroseismic sources can be used alternately (Flip-Flop mode). If you choose the Work by Acq (page 165) option, the system can start shooting a Source Point with multiple acquisitions to stack, but suspend it and let the focus jump to another source and Source Point. In that case, use this field to tell the system how many (up to 4) Source Points can be opened, i. e. suspended.

• Maximum simult VP: (1 by default).

• Maximum nb of samples: (12001 by default).



1

• Max user header length: (4096 by default). Maximum length of the External Header in the SEGD file. The following information is appended in that header:

- Information from the shooting or navigation system,

- User information from the Config client window’s setup,

- Source comment from Operation client window.

Figure 1-21 Process scaling parameters

• Time broadcast delay on LAUXX connection:

• Time broadcast periodicity:

• Max nb of pending rtv:

• Max nb of numerical aux:

• Max banner string length:

• Eof is immediate:



1
• 3592 max number of rwer:
• Disk warning percent on:

• Disk warning percent off:

• Max number traces to plot:

• LAU start timemout:

• LRU start timeout:

• LAUXX connection delay:

• LRU control timeout:

• Retrieve question timeout:



1


Chapter

2 Installation setup

This chapter describes the Installation setup window. It includes the following sections:


• The 428XL Install window (page 39)


Installation setupOverview

2

OverviewClicking on the “Install” icon in the 428XL launcher bar opens a window to be used when you install the system or whenever you install a new software version, or another type or vibrator electronics, or if you change the number of LCI428 units, etc.

After making the desired selections in the “Install” window, click “Apply”. This reboots the server workstation.

WARNING

The new settings will not take effect until the server workstation has booted up.

In addition, after adding or changing an LCI428 unit, the system may ask you to reload LCI software (see 428XL Installation manual).


Installation setupThe 428XL Install window

2
The 428XL Install window
In this section:

• Seismic recording instrumentation (page 39)

• Peripherals (page 42)

• Mobile Receiver Unit (MRU) (page 44)

• Export mode (page 45)

Seismic recording instrumentation.

Figure 2-1

Instruments On FieldThese buttons allow the system to customize the graphic user interface, depending on the instrumentation to be used. The specific parameters



2

and/or commands attached to a type of instrument are hidden and disabled unless and until you choose that type of instrument in this window.

Disk BufferThe system uses a file repository in which it temporarily stores your SEGD files until the Export process can accept them. You can choose between the following two disk options for the file repository:

• Local Disk: the file repository will use the “/var/dump” directory on the local disk of the server workstation.

• JBOD FC: the file repository will use an external disk via a Fibre Channel (a fibre optics port is required on the server workstation).

The files can be arranged in different manners in the repository (see Backup Settings on page 57).

LCIChoose the number of LCI boards you wish to use, enter the network address of each of them in the associated fields. You can choose any address from 172.30.201.1 to 172.30.201.4

LicenceThese fields are used to enter the necessary passwords to enable the software packages you wish to use.

• e-428: This field is used to enter the password supplied to you by Sercel for your system (that password is dependent upon the number of client workstations you wish to use, the number of traces, the Host Identification of the server workstation, and the 428XL software version).



2

Figure 2-2

• Plotter: The licence for plotters cannot be typed on the keyboard. It may be supplied to you on a floppy disk, or CD-ROM, or USB key or any appropriate medium. You can also download the licence file and save it to the server workstation’s disk (e. g. to the /tmp directory).

The Info... button allows you to see if any licence is already installed.

To install a plotter licence:

- Insert the medium (CD-ROM, etc.) containing the licence file, or copy the file to workstation’s disk,

- Click on the Browse... button and select the licence file.

- Click on Install. A warning box may appear, asking you if you wish to install a licence. If you choose to do that and a licence already exists, you are going to overwrite that licence.

- Note: If the mention “1-jan-0” appears in the warning box, it should not be understood as an expiry date. Instead, this means the licence is unlimited.

- Click OK. This installs the plotter licence.



2

- Wait for a dialog box to appear to say if installation was successful.

- Click Apply. This reboots the server workstation.

Peripherals

Figure 2-3

Nb of DPG modulesThis field is used to specify how many DPG vibrator controller modules are attached to the system.

Vibrator typeChoose the type of vibrator electronics used for vibroseismic sources if any:

• VE432: to be selected if a VE432 from SERCEL is connected.

• Other: to be selected if any other type of vibrator electronics is connected.

Blaster typeChoose the type of blaster used for implusive sources if any:

• SHOT PRO (PELTON)

• SGS

• BoomBox

• SHALLOW



2

• MACHA

• OTHER (any type). With this option, the data from the shooting system is not processed.

Note If you select the “Connected with LSI” option:

- the indicator LED on FDUs, otherwise used as a test result indicator, is used to tell the shooter whether he is allowed to connect/disconnect an LSI between two links.

- you cannot launch a new shot until retrieval of the previous one is complete, whatever the field equipment and the shooting method used.

Number of plottersChoose the appropriate option (1 or 2) depending on the number of plotters attached to the system.

Plotter typeChoose the appropriate option (12 inch or 24 inch plotter).

Enter a name for each plotter in the associated “Name” field. The name will appear in the Plotter main window to identify each plotter.

MAC address: (Media Access Control address). This field is used to enter the hardware address of the plotter card, in the case of a plotter with an Ethernet port.



2

Mobile Receiver Unit (MRU)

If a tracking box is connected to the workstation (i.e. if you wish to implement the vehicle tracking function), activate the Use MRU button. As a result you have to do the following:

• From the “GPS Port 1” button, select the serial port to use for the vehicle tracking function. The “Base Port” button allows you to choose a second serial port to be used for service messages from the tracking box.

• From the “Driver Type” button, select the protocol used by the tracking box.

• Enter the password for the vehicle tracking function into the “Licence” field (or else communications with the tracking box will not be allowed).



2

Export modeYou can record your SEGD files to cartridges and/or export them to remote disks attached to the local network.

Tape driveThis option is used for traditional recording to one or up to four cartridge drives (to be selected from the associated button).

NFS ServerThis option allows SEGD files to be exported in real time to one or two disks simultaneously. To attach a remote disk to the local network, see 428XL Installation Manual).

FTP ServerUse this option if you wish to export records to an FTP server attached to the local network.

Figure 2-4

To install a NAS disk or a file server, 428XL Installation Manual.

172.27.128.2

(172.27.128.x.)

172.27.128.1GUI

172.27.128.41 FileZilla

172.27.128.99

Local network

ObserverFTP user

NFS server

428XL server



2


Chapter

3 Configuration

This chapter includes the following sections:

• The main window (page 48)

• The Setup menu (page 52)

• On Line/Off Line (page 58)


ConfigurationThe main window

3

The main windowIn this section:


• Customer Support (page 49)

• Copyrights (page 49)

• Identity Card (page 50)

OverviewThis window serves two main purposes:

• Firstly, it is used to set up some basic parameters at the beginning of a survey, for instance the sample rate.

• Secondly, it is used to control and initiate communications with the Line Controller Interface each time the system is switched on.

An additional task is to report on the current hardware and software configuration of the system, via the Identity Card.

Figure 3-1

Note You can shrink/expand the window by clicking in the Activity area.

Click to shrink or expand



3

Customer Support

Please note SERCEL Customer Support Hot Line with our dedicated phone number:

- Outside FRANCE +33 2 40 30 58 88

- In FRANCE 02 40 30 58 88

This allows you to get in touch with our SERCEL Customer Support Department, at any time and seven days a week, to ask any question related to the use of your SERCEL equipment.

One of our experienced, english speaking Customer Support Engineers will make every effort to give you any technical support you need.

The Hot Line includes a vocal mail box for calls outside normal business hours: just leave a spoken message and we will get back to you first thing in the morning (including Saturdays and Sundays).

SERCEL is committed to offering you our closest support for the success of your field operations.

Copyrights

Clicking on this button in the 428XL main window opens a box providing information on how to call the Customer Support Department for help.

Clicking on this button displays the list of copyrighted software and libraries used in your 428XL Graphic User Interface.



3

Figure 3-2

Identity Card

Figure 3-3

Clicking on this button displays a description of the configuration of your system (Software version, software patches installed, passwords, workstation configuration, plotter type, hardware configuration of 428XL Line Controller Interface, etc.).



3

Of particular note is the following information:

- Host I.D.

- Software Version.

- Passwords (and LCI board numbers).

- Maximum number of client user sessions allowed.

- Module Type (428).

The Customer Support Department will solve your problem more quickly if you provide them with a detailed description of the configuration of your system, using the Identity Card command.


ConfigurationThe Setup menu

3

The Setup menuIn this section:

• Crew setup window (page 52)

• User Info setup (page 55)

• SEGD setup (page 56)

• Disk Record setup (page 57)

Crew setup windowNOTE: You are not allowed to change these parameters unless and until the line is turned off.

Figure 3-4

Sample rate(1/4, 1/2, 1, 2 or 4 ms)

This option button allows you to specify the sampling interval to be used on all traces.



3

Filter Type(8N_Lin, 8N_Min).

Each 428XL channel has a built-in Digital Signal Processor that performs high-cut filtering, depending on the option selected in this setup window.

“N” stands for the Nyquist Frequency, i.e. half the sampling frequency. The available filters have a -3 dB point at 0.8 times the Nyquist Frequency, i.e. 0.4 times the sampling frequency:

- 100 Hz @ 4-ms.

- 200 Hz @ 2-ms.

- 400 Hz @ 1-ms.

- 800 Hz @ 0.5-ms.

- 1600 Hz @ 0.25-ms.

They feature a slope of about 370 dB/octave. The pulse response ringing, however, decays slowly.

The attenuation is at least 120 dB for all frequencies above the Nyquist Frequency, preventing any aliasing effect.

The 428XL allows the user to choose between:

- linear-phase type or

- minimum-phase type.

The amplitude spectrum does not depend much on the type of filter (linear or minimum phase), unlike the phase spectrum.

Linear PhaseThis type of filter is ideal as far as phase considerations are concerned, as all the frequencies are delayed by the same amount. That delay is set to zero in the 428XL.

In return, this kind of filter has a pulse response with leading ringing (“precursors”) as well as lagging ringing (actually, the pulse response is symmetrical with respect to time 0).



3

Minimum PhaseThe minimum phase type is causal, i.e. its pulse response, much like analog filters, starts at time 0, peaks and then rings (no ringing prior to the peak).

The delay, however, somewhat depends on the input frequency.

Default Line Data Rate(8 or 16 Mbits/s) This option button sets the default data rate for all acquisition lines. To determine which option to choose, you need to know which type of field electronics is used.

- The FDU428 field electronics supports both 8 and 16 Mbits/s data rates.

- The FDU408 field electronics supports only the 8 Mbits/s option.

WARNING

If any FDU408 electronics is deployed and you choose “16 Mbits/s”, it will not be seen by the system unless you use the The Form Line setup (page 116) to change the data rate to 8 Mbits/s on those line segments.

Time ManagementThis option button allows you to choose which clock to use to determine the time of shots:

• Internal Clock: shot time is synchronized on the server workstation’s clock.

• Source Controller: shot time is synchronized on the source controller (e. g. for explosive operations).

• NTP Server: shot time is synchronized on an NTP server’s clock. You have to enter the NTP server’s IP Address into the associated field.

• GPS: shot time is synchronized on the GPS time, if the VE432 or the blaster controller is equipped with a GPS receiver.



3

Post Annotation LoggingIf the data for some fields in any SEGD file is not available at the moment the file is generated, this option determines whether or not the system is allowed to update those fields at a later date (when the data is available).

User Info setupAn External Header appears in every SEGD file generated by the system. Selecting “User Info” from the “Setup” menu opens a window that allows you to enter any extra information not supported by the standard header (ASCII characters) that you wish to be recorded in the External Header. It can be left blank if not required.

Figure 3-5

The size allocated to the External Header depends on which options you choose in the SEGD setup menu.



3

SEGD setupIf you choose the “Advanced” rather than “Standard” option, you can choose between the following SEGD format options:

Figure 3-6

SEGD LevelYou can choose between Revision 1 (Standard) and Revision 2 (providing better efficiency of using high density recording media, and supporting the use of tapes with physical and electronic readable labels).

Number of Record Channel Sets You can choose between the following options for the number of channel sets per record: 16 (Standard), 32 or 64.

External Header SizeYou can choose between the following options for the size (kByte) of the External Header: 1 or 64 (standard); 1 to 28 in 4-kByte steps (Advanced).



3

Disk Record setupThe system uses a file repository in which it temporarily stores your SEGD files until the Export process can accept them (see Disk Buffer on page 40). The Disk Record setup window lets you choose the way the system will arrange the files in the SEGD repository.

Figure 3-7

Disk record mode• The “Standard” mode will save your production files to “/var/dump/

normal” and your test files to “/var/dump/test”.

• The “Advanced” mode may create subdirectories, depending on which “Backup Settings” option you select.

Backup SettingsThe files can be arranged in three different manners:

• Flat: all files are saved to the same directory (production files are saved to “/var/dump/normal” and test files to “/var/dump/test”).

• Swath Name: same as with the “Flat” option, but a subdirectory is created for each swath.

• Swath Name and Julian Day: same as with the “Swath” option, but for each swath, a subdirectory is created for each julian day.


ConfigurationOn Line/Off Line

3

On Line/Off LineClicking “Off Line” inhibits data acquisition and recording, and enables local functions on the Graphic User Interface. You are then allowed to make any changes to parameter settings in the “Setup” menu in each main window.

Clicking “On Line” enables data acquisition and recording. This also automatically performs a Look function, as well as an instrument test on the auxiliary traces.

Figure 3-8

The “Activity” box shows the progress of the data flow, in the form of traffic lights for each stage in the 428XL. When the process stage is idle, all three lights are off. Otherwise, the colours should be interpreted as follows:

• The green light means the data stream is being processed or dumped to the next process stage.

• The orange light comes On if the processor is unable to dump the data presently being processed to the next stage, for example because “Manual” instead of “Auto” is activated in the “Export” or “DPG” main window.

• The red light comes On if the processor is unable to process the data presently contained in the stage, or unable to dump the processed data to the next stage (therefore unable to accept any more data).

Acquisition length downcount or delay downcount

Current file number

Number of shots being processed

Number of shots to retrieve



3

The following indicators may appear:

• ACQ (Acquisition): The green light means that acquisition is in progress. The orange light comes On during the programmed delay, if any, between acquisitions, or if seismonitor in the Line main window is running. The red light means no acquisition can be performed at the present time (e. g. because there are too many shots to retrieve).

At the foot of the ACQ light is a time counter, preset to the acquisition length value (including any programmed delay) at the start of each acquisition, that indicates the time still to elapse before the present acquisition (or delay) is complete.

• RTV (Retrieve): The green light means that the seismic data collected from the FDUs, and stored in the LAUs, is being retrieved by the central control unit. The orange light means that acquisition is complete but it is not entirely retrieved. The red light means retrieval is no longer possible. The counter at the foot indicates the number of shots still to be retrieved (max. 2).

In addition, the following processing stages may appear in the Activity window:

• PROC. The green light means data is being transferred from line interface to the processing queue, and/or Noise Elimination and/or Correlation is in progress. The orange light means the processing is no longer performed in real time. The red light means no processing can be performed at the present time. The counter at the foot indicates the number of shots being processed.

• DPG (if a VE432 DPG vibrator controller is installed).



3


Chapter

4 Line



• Topographic views (page 64)

• Numeric views (page 77)

• The Survey setup (page 79)

• The Layout setup (page 86)

• The Spread Type setup (page 95)

• The Look setup (page 100)

• LAU Leakage setup (page 101)

• Advanced layouts (page 103)

• Test functions (page 107)

• The Form Line setup (page 116)

• The Synthetic setup (page 121)

• The Download setup (page 126)


LineThe main window

4

The main windowThe Line client window provides access to all of the test and utility functions necessary for management of seismic lines and spreads.

The main window gives a graphical or numeric representation of all field equipment connected to the Line Controller Interface, together with Sensor and Instrument test results. Selective colour coding is used to highlight problems that may affect data quality.

Figure 4-1

The View menu allows you to customize the main window by choosing one or more views to display. Then you can resize your display panes by dragging the desired border.

For details on how you can arrange the views and toolbars as you would like them, see the Hands-on guide (page 22).

Line and spread parameters are programmed through the Setup menu. See The Survey setup (page 79) to describe the survey, and The Layout setup (page 86) to generate markers.


LineThe main window

4

As soon as the line power is turned on, all the field units connected become alive and can be viewed in the main window.

FDUs can be in one of two states: acquisition (seismonitor or recording) or field update (the rest of the time). As a result the database is continually updated.

Just after the line power is turned on, all FDUs are in field update mode (unless no markers are defined). As a result, Resistance, Tilt and Leakage Sensor tests are performed in real time and can be viewed.

Whenever a new field unit is laid out, it does not appear in the topographic view until the spread is formed again. If the spread remains the same for consecutive shots (VPs) in continuous mode, no spread forming is performed, so any new unit laid out will not be visible unless you program a Look between VPs in the Operation main window (see Look on page 160). If any Sensor tests are selected in the The Look setup (page 100), they are performed too (but if the Resistance value exceeds the specified limit, e. g. if nothing is connected on the channel input, Tilt and Leakage tests are not performed, even if they are selected in the Look setup).

Note simply setting a Delay between two shots or VPs will also cause a Look to be executed.

While active FDUs are collecting the data during acquisition, all passive ones are still in field update mode and their states are continually updated on the display if they are in lines that are not involved in the acquisition. You can see right away if any extra units have been connected to those lines, or if any sensors or cables (called paths) are at fault. Any faulty elements, including cables, are displayed in red. Connectors are shown too (to do that, the system uses the Link properties recorded in each FDU).


LineTopographic views

4

Topographic viewsIn this section:

• About topographic views (page 64)

• Sensor view (page 66)

• Instrument view (page 68)

• Battery view (page 70)

• Seismonitor (page 71)

• Working with graphic views (page 72)

About topographic viewsTopographic views provide geographic displays of the results available from field updates.

Use the View menu or toolbar buttons to choose the type of information to display:

Figure 4-2

• Information on the survey (“Sensor” topo view).

• Information on field units (“Instrument” and “Battery” topo views).

• Sensor noise level (“Seismonitor” topo view).

Whatever the type of information displayed, the other results are just one click away.



4

Figure 4-3

(1) The left-hand pane displays the whole survey. See Zooming (page 73).

(2) Click on these buttons to expand or collapse the left-hand pane. Drag the vertical border to resize the two panes.

(3) The right-hand pane displays a magnified view of the area encompassed in the red frame selected in the left-hand pane. See Zooming (page 73)

(4) The legend shows the programmed limits for QC results. With the mouse pointer resting on any element in the graphic view (Sensors/Seismonitor/Instrument/Batteries) a tip box appears that shows the identification of the element and its QC result if any is available, depending on the choice made with the test option button. The relevant legend automatically appears as the tip box shows up.

In the graphic view, the tested elements are green if within the limits, red or blue otherwise. The limits for the sensor tests are

(1) (4)

(5)(6)(8)

(3)(2)

(7)



4

adjustable through the Survey Setup menu (using the Apply Sensors button).

(5) Use this button to turn on/off the power supply to the lines.

(6) Location of the mouse pointer within the graphic pane.

(7) Zoom out button: restores the previous zoom factor.

(8) Reset button: removes zooming.

Sensor viewThis view shows the topographic stakes and the types of sensors in the survey.

Figure 4-4

(1) Use this button to show or hide the sensor type in the graphic view. (The selected sensor type number appears inside the icon).

(4)(3) (5)(2)(1)



4

(2) Use the Sensor QC Type button to select the type of sensor whose test results you want to display.

(3) This button looks for the units connected. and launches the Sensor tests selected in the The Look setup (page 100). See also Sensor tests (page 112).

(4) This option button is used to choose which type of sensor QC test to launch (with the Go button) and display.

(5) The Go button provides a shortcut for the test functions available from the Test Setup menu. (See also Test functions on page 107). It launches the selected QC test on the selected units. (If no units are selected, then the test is performed on the whole survey). This clears the test results, and the units are shown in blue until the test is completed and new results are available.

To select a set of units in the graphic view, see To select one or more elements (page 72). After you launch a test function on any unit, a grey background appears on that unit in the graphic view, meaning that the unit is busy.

The colour of each sensor icon depends on the limits programmed for the Sensor test selected using the option button (Resistance, Tilt, Noise, Leakage). To change the Sensor test limits, see Sensor type (page 83) in the description of The Survey setup .

Sensor icons in the graphic view are shown in:

• Green if within the Sensor test limits.

• Red if out of Sensor test limits.

• Light blue if not tested.

Any mute sensor appears as a blue cross (no sensor is detected).



4

Instrument viewThis view shows all the field equipment connected in the survey.

Figure 4-5

(1) This button looks for the units connected.

(2) This option button is used to choose which type (Distortion, CMRR, Gain error, Phase error, Noise, Crosstalk) of instrument QC test to launch (with the Go button) and display. You do not need to click on Go to get the results from self-tests (Auto Test option).

(3) The Go button provides a shortcut for the instrument test functions available from the Test Setup menu. See also Test functions (page 107). It launches the selected QC test on the selected units. (If no units are selected, then the test is performed on the whole survey). This clears the test results, and the units are shown in blue until the test is completed and new results are available.

(1) (2 (3

FDU



4

To select a set of units in the graphic view, see To select one or more elements (page 72). After you launch a test function on any unit, a grey background appears on that unit in the graphic view, meaning that the unit is busy.

The buttons in the upper-left corner allow you to highlight or dim some of the elements for better legibility..

Figure 4-6

By default, the Instrument graphic view displays the results from self-tests. The colour code is as follows:

• Green: The unit is identified and its self-test is correct.

• Orange: The unit is identified but no self-test has been performed (because of a transmission problem).

• Red: The unit cannot be used, or its self-test failed. See Numeric views (page 77) for details.

• Grey: There is no Marker on the line segment.

Stakes

LAUXFDUCable path 428XL



4

Battery viewThis view shows the battery-operated units deployed.

Figure 4-7

With the mouse pointer resting on any battery-operated unit, a tip box appears, showing the type of the unit, its serial number and its power supply voltage. The legend at the top of the window shows the programmed limit for the battery voltage, which is adjustable using the Threshold slider button.

The icons in the Battery view are shown in green if the battery voltage is above that threshold, red otherwise.

Legend

Tip

Threshod adjust



4

SeismonitorThe Seismonitor topographic view allows you to view the sensors in terms of input signal rather than sensor type.

It shows the active spread:

• Active sensors appear as green squares,

• Dead sensors appear as red squares,

• Mute sensors appear as dark blue squares,

• Stakes defined with no sensors appear as yellow crosses.

When the Seismonitor pushbutton is activated, this view also allows real-time noise monitoring: the level on each receiver is represented using eight 6-dB steps for both the height and colour (from green to red) of each receiver icon, depending on the gain selected for Seismonitor. The red colour step corresponds to the highest step in the level scale.

Figure 4-8

The seismonitor gain is applied to both seismic and auxiliary traces.

The Gain slider button, in conjunction with the Sensor Type option button, allows you to adjust the Seismonitor gain for each type of sensor.

Used to choose the seismonitor gain

The scale adjusts itself according to the gain

chosen

Used to choose which sensor types to show or

hide

Used to choose which sensor type gain to adjust with the Gain slider button



4

Note Naturally, the Sensor noise on radio-type channels is not viewed in real time. The radio-type channels noise display is only refreshed each time you use the Look function.

Working with graphic views

To select one or more elementsWith the mouse pointer resting on the first unit to be selected, press the centre button of the mouse. Hold it down while dragging the pointer to the last unit to be selected, then release it. A red background appears on the selected units.

Figure 4-9 Selecting elements in graphic views

You can copy the selected area using the Control+ C shortcut (the message “Copy Ready” should appear at the foot of the window) and paste it into the Absolute Spread Setup window to create a spread setup.

If you launch a test with the buttons in the upper-right corner of the graphic pane after selecting a set of units, the test is only performed on the units selected. The selection is replicated (in the form of an absolute spread description) in the Test Setup window accessed via the Functions menu.

To select a single unit, use the same method with a sufficient zoom factor.

To unselect, click anywhere in the graphic pane.

Release

Press



4

ZoomingWith the mouse pointer resting anywhere in the graphic pane, press the left button of the mouse. Drag the mouse pointer slowly in any direction. This causes an elastic frame to show up that enlarges until you stop dragging the mouse pointer. Release the mouse button. As a result, the spread area encompassed in the elastic frame occupies the entire right-hand pane.

Figure 4-10 Zooming

To view a channel’s QC dataWith the mouse pointer resting on a receiver position, a tip box appears, showing the type of the unit, its serial number and the QC result. The relevant legend automatically appears at the top of the window, showing the programmed limits for that test.

Figure 4-11 Viewing a channel’s QC data

Release

Press mouse left button

Mouse location

Only the QC result chosen with the option button is shown.

Legend

Tip



4

Still with the mouse pointer resting on a receiver position, pressing the right-hand button of the mouse causes a menu to pop up. Selecting Properties opens a window showing details on the receiver position. The Properties of an FDU include its identification, status, and all available QC results. Also in the Properties of an LAUX are its IP address and Booster power supply voltage (48 V).

Figure 4-12 Viewing Instrument properties

Right-click shortcutsWith the mouse pointer resting on an element in the graphic Instruments view, the menu that pops up when you press the right-hand button of the mouse may prompt one or more contextual shortcuts that let you display or change properties or parameters of the element.

For example, you can turn a receiver position mute without going through the Setup menu: you simply have to right-click on the desired position and select “Set Mute” from the menu that pops up. The relevant setup (e. g. the Layout setup in this example) is automatically updated.



4

Checkerboard viewWith many units to be shown in the graphic view, the system may decide to switch to the checkerboard view mode because there is no room for all icons.

In the checkerboard view mode, icons are shrunk so that they can fit in the graphic pane. Colours are still significant but control units (LAUX, LAUL) and anomalies are emphasized so that you can spot them easily. Then you can zoom in to see details.

All the FDUs making up a link are shrunk into a single rectangular icon whose colour reflects the global QC of the link: faults (shown in red or orange) take precedence over any other QC values, i. e. the link’s icon turns red if any one status in the link is at fault.

PathsLinks can be viewed using the Cable Path button in Instrument views.

Figure 4-13

The following conventions are used for cable paths:

• Green: OK.

• Orange: Sensed, but a transmit error was encountered.

• Red: A problem was encountered at the end of the cable.

End of a link (connector)

Detour



4

The graphical view of paths helps you isolate any transmission trouble: if the system finds the transfer time from a unit to the next is inconsistent, the suspect path is displayed in red and, if the path is included in the active spread, an alert window pops up when you click on Go to launch an acquisition.


LineNumeric views

4

Numeric viewsUse the View menu or toolbar buttons to choose which type of data to display.

Figure 4-14 Sensor numeric view

Numeric views display the available results in tables.

• Those results which do not fall within the limits specified in the Setup menu are shown with a red background.

• All columns are resizable. Adjust the width if any value fails to fit in. (With the mouse pointer resting on the border of a column, left-click and drag the border as required).

• You can show or hide columns by right-clicking in any column heading and selecting Customize (see Figure 1-14).

• Left-clicking on the heading in any column causes the data in that column to be sorted in ascending order. Clicking one more time reverses the order, and so on.

• After you connect a new unit to a line, the unit is added at the top of the table. The list is not sorted until you click on a column heading.

• The results are cleared each time a test function is launched.

Use scrollbar to view hidden columns

Drag border to resize


LineNumeric views

4

Figure 4-15 Sensor numeric view (continued)

Figure 4-16 Instrument numeric view

For an LAUL or LAUX, the “Booster Failure” column shows the status of the +24 V and -24 V power supplies (a failure is reported if the voltage is below 24 V) and the “Leakage error” column shows the result from the leakage test (see LAU Leakage setup on page 101). For an LRU, leakage cannot be measured.

A History views allow you to view the Serial number, Line number, Point number and geographical position of each unit, along with the date and time when it was last seen (Last Access) and first seen (Creation Date) in the survey.


LineThe Survey setup

4

The Survey setupIn this section:

• General (page 79)

• Survey (page 80)

• Point Code (page 82)

• Sensor type (page 83)

GeneralYou open this window by selecting Survey from the Setup menu.

Figure 4-17

It is used to provide information about the area of the survey prospect where the crew is working. You access three categories of information using the three tabs described in detail below: Survey (page 80), Point Code (page 82) and Sensor type (page 83).

To make changes to any row in the list box, double-click on it, fill in the fields above the list, then click Add or Change or Delete, as required.

To save the current settings, click Apply All with the lines turned OFF (Field Off). This activates the choices made with all three tabs. In contrast, whether the Lines are on or off, you can click Apply Sensor to activate only the test result limits settings made using the Sensor tab.

List box (empty)

Input fields



4

To revert to the former settings, click Reset instead of Apply.

SurveyTo determine the crew’s survey prospect area, you have to specify the start and end points of the lines, together with any gaps caused by obstacles or whatever. To do that you’ll click on the Survey tab.

Figure 4-18 Survey setup

LineThis index box is used to enter line numbers.

Tip: For example, entering 10-60/10 in the “Line” index box will generate lines 10, 20, 30, 40, 60 in one click on Add.

Line numbers do not need to be arranged in any order. For instance you may well wish to insert line 70 between lines 30 and 40: click line 30 in the list box (its number appears in this index box), enter 70 in the index box and click Add.

It is important, however, to understand that the graphic display in the main window reflects the Survey setup. In other words, seismic lines will be shown on the screen in the order in which they appear in this list box, and not necessarily in the sequence they are laid out on the ground or connected to the recording instruments.

Note The traces recorded in the SEGD file will be in the same order as in the Survey setup.

Receiver points

100-103p1,106-110p1,111-115p2,116-120p3

Different Point CodesGapPoint Code



4

If line numbers are arranged in ascending or descending order, you can easily reverse the order using the Reverse button as required.

Receiver SectionThe Receiver Section field is used to assign a Point Code to each Receiver Position in each line.

The syntax for the Point Code is p_ (example: p1). The Point Code determines the type of sensor used. You define Point Codes in the window accessed by clicking on the Point Code tab (see page 82).

On lines that do not use the same point code everywhere, you have to split the description of the receiver section into as many series of adjacent stakes with a common point code as necessary.

In the example provided in Figure 4-18 on page 80, stakes 100 to 110 have the same point code (p1) but the series of receiver positions is split because a gap with no channels is planned between stakes 103 and 106.,

Figure 4-19

The stakes must be numbered in ascending order, usually with an increment of 1 but you can use an increment other than 1.

This is the graphical display resulting from the above example of survey description.

100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120

5

10

30

20

40

50

60



4

Tip: Example with an increment other than 1 for the receiver positions: entering 100-150p1/10 as a receiver section will generate receiver positions 100, 110, 120, 130, 140, 150 in one click on Add.

Point CodeSome applications require the use of different types of sensor within the same spread. An example would be a transition zone survey, where geophones are employed on land and hydrophones in water.

To specify the type of sensor to be used in a receiver section, you assign a Point Code to it (see Survey on page 80).

You define Point Codes in this window:

Figure 4-20 Point Code setup

NbUsed to enter Point Code numbers. The system will automatically add the letter “p”. You must define at least one Point Code.

LabelUsed to identify the Point Code in plain.



4

Sensor Type Syntax: s_ (example: s1+s2).

Used to enter the sensor type or types associated with the point code. Sensor types are defined in the window accessed by clicking on the Sensor tab.

Sensor typeWhen Sensor tests are to be performed, the electrical characteristics will not necessarily be the same across the entire spread and therefore it may be pointless to apply the same resistance, tilt (pulse response) and noise test limits everywhere. Instead, the system allows several sets of limits to be specified, each one appropriate to a particular sensor type. It is then sufficient to define the zones in which each type of sensor can be found, using Survey (page 80), and the system will automatically apply the relevant limit for each measurement.

You can define different sensor types in this window.

Figure 4-21 Sensor setup

NbUsed to enter Sensor Types numbers. You must define at least one Sensor Type.



4

LabelUsed to identify the Sensor Type in plain.

ContinuityUpper and lower limit for the sensor impedance. Any channel with a sensor impedance falling outside the range specified in the Min and Max fields is reported at fault in sensor views (and shown in red in graphic views).

TiltMaximum geophone tilt percentage. Alert threshold in the display of Sensor Tilt test results.

NoiseMaximum RMS noise level. Alert threshold in the display of Sensor Noise test results.

LeakageAlert threshold in the display of Sensor Leakage test results. The Leakage test measures the global leakage resistance between the seismic channel and the earth ground.

SEGD Code

Figure 4-22



4

Clicking the button associated with this field causes a list box to pop up so that you can select the SEGD code of the type of sensor used. This code has no effect on the performance of the system. It is only written to tape (byte 21 in block 1 of the Trace Header Extension).


LineThe Layout setup

4

The Layout setupIn this section:


• Markers (page 87)

• Auxiliary channels (page 90)

• Mute channels (page 94)

General

Figure 4-23

Having defined the lines that will be used in the survey, using The Survey setup (page 79), it is necessary to provide information for the central unit to capture the actual layout of those lines, using the layout setup window.

You open this window by selecting Layout from the Setup menu.

You don’t have to supply the location of each and every element in the survey: you only have to create a marker (fully identified with its unit type, serial number, topographic stake number) in each line segment. This will enable the system to automatically see how your field equipment is deployed. In this window, you also specify the location of

List box (empty)

Input fields



4

auxiliary channels, detours, and inactive channels. You also have to describe all radio telemetry units.

Note The selection you make by clicking on any row in the list box is reflected in the main window’s graphic view: the cursor automatically moves to the selected unit.


To save and enable your changes, click Apply. (To revert to the former settings, click Reset instead).

MarkersUse this window to specify the location, unit type and serial number of at least one unit (FDU, LAUL, LAUX or LRU) in each line segment actually connected. After you define the markers, the system is able to collect the status of all units connected, as soon as lines are turned on. Then it will continually update the view in the main window..

Figure 4-24 Marker setup

Tip: To enter a marker, you can drag and drop a unit from the main window (Instrument graphic view) to the markers list box.

At least one marker on each line



4

Box TypeAs its label suggests, this field is used to choose the type of unit (LCI428, LAUX428, etc.). Select the type actually implemented at the location chosen as a marker

S. N.Serial number of the unit actually implemented at the location chosen as a marker.

Line NameUsed to specify the number of the Line the marker is attached to.

IMPORTANT

Each line should have at least one marker. If the line is composed of several segments, enter a marker on each segment.

Below are two examples:

Two line segments with a transverse cable used as a detour

Figure 4-25

Transverse cable

Enter one marker for this line segment

Enter another marker for this line segment



4

End-to-end line segments with no wireline connection

Figure 4-26

Point NbUsed to specify the Point Number (i. e. stake number) of the location used as a marker.

Note By convention, an LAUL or LAUX assumes the number of the first topographic stake encountered on its Low side. (Remember topographic stakes are defined in the Survey Setup).

Figure 4-27

Channel Nb Used to specify the channel number implemented at the location used as a marker, in the case of a multi-channel unit.

No

wire

line

conn

ectio

n

Marker

Marker

Enter one marker for this line segment

Enter another marker for this line segment

To set a marker on this LAUX, enter 111 as Point Number

110 111 112 113



4

Marker IncrementTypically, the Marker Increment is set to 1, meaning that a receiver channel is deployed at each stake number.

Figure 4-28

To implement a Receiver Position (i. e. a receiver channel) every “n” stake numbers on a line segment, enter “n” into the Marker Increment field. See Logical line mapped with several physical lines on page 105.

ReversedTypically, the “Reversed” button should be left unticked.

This button is used to reverse the direction of the assignment of receiver channels to receiver positions over a line segment.

Auxiliary channels

Figure 4-29 Auxiliary channel setup

Box Type S. N. Line Name Point No. Marker Incr.

FDU-428 xxxx 10 112 1

LAUXFDUxxxx

Line10

Marker

Marker Setup

109 110 111 112 113 114 115



4

Use this window to describe auxiliary channels. You can use FDUs connected direct to the 428XL control module and also FDUs located anywhere in the spread.

Tip: To enter an auxiliary channel, you can drag and drop a unit from the main window (Instrument graphic view) to the list box.

In the topographic view of the spread, all auxiliary channels are gathered at the record unit position.

NbRow number in the list box.

LabelUsed to assign a name to the Auxiliary channel (e. g. Pilot). That label is used in the Operation main window to describe the type of processing to be performed. See Correlation with (page 143).

Box TypeUsed to choose the type of unit used for this auxiliary channel (FDU, FDU428, FDU2S, etc.).

S. N.Used to enter the Serial Number of the unit used for this auxiliary channel.

Channel NbUsed to specify the channel number of this auxiliary channel, in the case of a multi-channel unit.

GainUsed to choose the preamplifier gain for this auxiliary channel. See the gain code table on page 96.



4

CommentsUsed to enter any comment you think necessary, for example if the Label is not self-explanatory.

DetourUse this window to specify the location of detours, if any, between receiver positions. All units within a detour will be inactive (unused).

Figure 4-30 Detour setup

Below is a typical example where a detour is set between two adjacent receiver positions.

Figure 4-31

Low Box TypeUsed to specify the Type of the adjacent active unit located ahead of (on the Low side of) the detour.

Unused units

Last active unit on Low side (enter its Serial No.

into Low S. N. field)

First active unit on High side (enter its Serial No. into High

SN field)

110 111



4

Low S. N.Used to specify the Serial Number of the adjacent active unit located ahead of (on the Low side of) the detour, meaning that the unit on the other side is the Low end of the detour.

Low Chann. NbIn the case of a multi-channel unit, use this field to specify the adjacent active channel ahead of (on the Low side of) the detour, meaning that the channel on the other side is the Low end of the detour.

High Box TypeUsed to specify the Type of the adjacent active unit located after (on the High side of) the detour.

High S. N.Used to specify the Serial Number of the adjacent active unit located after (on the High side of) the detour, meaning that the unit on the other side is the High end of the detour.

High Chann. NbIn the case of a multi-channel unit, use this field to specify the adjacent active channel after (on the High side of) the detour, meaning that the channel on the other side is the High end of the detour.

Stop MarkingTypically, the Stop Marking button should be left unticked.

This button is only used where a change is required in the automatic assignment of receiver channels to receiver positions. (See also Advanced layouts (page 103)).



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Mute channels

Figure 4-32 Mute setup

Use this window to specify the location of mute receiver points, if any. The channel from a mute receiver point is acquired, but its data is zeroed. In the case of multi-sensor receiver point, all channels are mute.

Tip: To enter a mute receiver point, you can drag and drop it from the main window (Instrument graphic view) to the list box.

Line Name, Point NumberUsed to specify the location of a mute unit.


LineThe Spread Type setup

4

The Spread Type setupIn this section:


• Absolute spreads (page 96)

• Generic spreads (page 97)

GeneralYou have to specify the complete acquisition spread to be used for each and every shot. The programming of these spreads can be done not only automatically via SPS files but also manually, using the editing tools provided by the GUI.

Figure 4-33 Spread type setup

In either case, a shorthand method of defining all of the channels to be used is available in the 428XL. The concept of a “Generic Spread” (generic means “Standard”) is especially helpful for manual programming. The alternative method uses “Absolute Spreads”, which are more suitable for automated programming.

To define a new spread in the list box, fill in the description, identification number and label fields, then click Add.


Enter the description of your spread here



4


Absolute spreadsAn absolute spread is defined in terms of line and stake numbers, for example: Line 10, from stake 101 to stake 103, then from stake 106 to stake 115. (It therefore follows that you need to define a completely new absolute spread every time the acquisition spread moves even by a single receiver point).

Figure 4-34 Absolute spread setup

Enter a colon (:) between the Line Number and the Receiver positions.

Enter a hyphen (-) to specify a series of Receiver positions.

Enter a comma (,) to specify a gap between two or more Receiver positions (or to specify series of Receiver positions with different channel gain codes (e. g. 106-110g1,11-115g2).

To describe another Line or set of Lines, press Return or type a slash character (/).

The system automatically adds “as” (abbreviation for “Absolute Spread”) ahead of the Identification Number in the list box.

Choose the gain code from the table below.

10:101-103g1,106-115g120:101-103g1,106-115g130:101-103g1,106-115g140:101-103g1,106-115g1

Gain code



4
Tip: A simple way of creating an absolute spread type consists of selecting the desired spread in the graphic view with the mouse, copying the selected area and pasting it into the Spread Type setup window. See Figure 4-9 on page 72.
Generic spreadsA generic spread describes the pattern of the active channels. The fundamental difference between an absolute and a generic spread is that generic definitions are always relative. You may wish to define one generic spread to be used throughout the life of a crew.

To take a textbook example, a symmetrical split spread could be defined as a number of lines with 100 stakes, a gap of 2 and then another 100 stakes. There is nothing in the basic definition that says where the spread should be implemented. If one or more receiver units fall outside the boundaries or within a gap specified in the Survey Setup, those channels, will not be implemented.

Figure 4-35

Gain Code Input scale FDU DSU

g1 1600 mv 0 dB 4 m/s²

g2 400 mV 12 dB 1 m/s²

Gen

eric

spr

ead Generic Line

Generic Line

Generic Line

Generic Line



4

Line

Figure 4-36

The description of generic spreads makes use of Generic Line Types that you define in this window. When you describe a Generic Line Type you assign a gain code to a set of channels. See the gain code table above.

Note If any receiver units are laid out between receiver points, they must be described as “skipped channels” in the The Survey setup (page 79) or “detours” in the The Layout setup (page 86).

Note To skip receiver points, enter rs in the description.

Use brackets to repeat sets of two or more gain codes, with a repetition factor placed ahead of the leading bracket. Below are two examples:

• 10(g1+g2) will describe 10 pairs of channels where, in each pair, the 1st channel has a 0 dB gain and the 2nd channel a 12 dB gain.

• 10(g1+rs) will describe 10 pairs of channels where, in each pair, the 1st channel has a 0 dB gain and the 2nd channel is skipped.

The system automatically adds the letter "l" ahead of the Identification Number in the list box.

50g1+50g2



4

Spread

Figure 4-37

When you describe a Generic Spread type you assign a generic Line Type to a set of lines. Line types are defined in the Generic Line window.

To skip lines, enter ls in the description.

Use brackets to repeat sets of two or more lines, with a repetition factor placed ahead of the leading bracket. For example 10(l1+ls) will describe 10 pairs of lines where, in each pair, the 1st line is L1-type and the 2nd is skipped.

The system automatically adds “sd” (abbreviation for “Spread Descriptor”) ahead of the Identification Number in the list box.

10l1+10l2


LineThe Look setup

4

The Look setupYou open this window by selecting “Look Setup” from the Setup menu. The Look function is used to see if any new units are connected, so as to display them in the Line main window.

Look• Manual: Each LAU will only identify the

connected units when you go to “Field On” or you click on the “Look” button.

If a disruption arises, only the units encountered on the connected line segment are re-identified by the LAU.

In the event of a transmission sync error, a red path appears at the output of the LAU controlling the line segment affected. You have to launch a manual Look to re-identify the FDUs located between the LAU and the disruption.

• Auto (default option): Each LAU continually looks for any new units connected so as to identify them.

On a line segment including an LSI, the automatic look is disabled: to see new FDUs, you must use manual Look in that case.

With TestsAfter each Look, whether Automatic or Manual, the Sensor tests you choose with these buttons (Resistance, Tilt, Leakage) will be performed on the FDUs identified.

The Resistance and Tilt tests are selected by default.

In “field update” mode, if the Resistance value exceeds the specified limit (e. g. with nothing connected on the channel input), the Tilt and Leakage tests are not performed, even if they are selected in this setup.

Figure 4-38


LineLAU Leakage setup

4

LAU Leakage setupA leakage sensor circuitry in each LAU senses any leakage arising between a conductor in the telemetry cable and ground.

The LAU Leakage command available from the Setup menu allows you to set an alert level. If the leakage current exceeds that alert level, the LAU reports a fault to the GUI. As a result, the LAU is shown in red in the Instrument topographic view and a Leakage error appears in the Instrument numeric view for that LAU.

Figure 4-39

The “Connections” column in the Instruments graphical view, and the properties of an LAU (available on a right-click) tell you which port(s) is (are) powered up, so you can see which port is affected by leakage. In the case of an LAUX, you can use the Form Line function to enable/disable its low or high port in order to discriminated between the two ports.

In each LAU, a leakage measurement is taken every 5 seconds, using the test circuitry shown on the simplified diagram below.

Leakage current displayed in red if

exceeding alert level.

Tells you which port is affectedAvailable from

Setup menu


LineLAU Leakage setup

4

Figure 4-40

Note: Leakage between the two telemetry pairs is not revealed by this test circuitry, but transmission may be lost as a result of such leakage.

+24 V

-24 V

ADC

FDUPwrSply

6.3 V

2.7 V

FDU

Rsense

Leakage current

Telemetry pair

Telemetry pair

Leakage

Leakage current

LAUL or

LAUX

Housing


LineAdvanced layouts

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Advanced layoutsSome fields or options (like “Marker Increment”, “Stop Marking”, “Reversed”) in the Setup windows make the deployment of 428XL field electronics extremely flexible. Below are textbook examples of advanced layouts that can easily be implemented:

• Logical line mapped with several physical lines (page 105).

• Detour with skipped receiver points (page 103)

• Snaking layout (page 104)

Detour with skipped receiver points

Figure 4-41

To implement this example:

• You have to set two markers (one on either side of the detour);

• In the Detour setup, you must choose the Stop Marking option. This will actually assign FDU No. yyyy to Receiver Position 114.

Box Type S. N. Line Name Point No. Reversed

FDU-428 xxxx 10 110

FDU-428 yyyy 10 114

Low Box Type Low S.N. Low

Chann NbHigh

Box Type High S.N. High Chann Nb

Stop Marking

FDU-428 xxxx FDU-428 yyyy

Marker FDU

yyyyFDUxxxxMarke

r

Marker Setup

Line10

Detour Setup

109 110 111 112 113 114 115



4

Snaking layout

Figure 4-42

An example of “snaking” layout is shown above. In the Detour setup window, create a detour on each change in the direction of the assignment of receiver channels to stake positions, each time choosing the Stop Marking option. In the Marker setup window, be sure there is a marker on either side of each detour, using the “Reversed” option where channels are assigned in decreasing order of stake positions.

The Marker position can be chosen elsewhere within each line segment, that is on any FDU, LAUL or LAUX belonging in the line segment. For

Box Type S. N. Line Name Point No. Reversed

LAUX-428 xxxx 10 108

FDU-428 vvvv 20 113

FDU-428 zzzz 30 109

LAUXFDUuuuu

FDUvvvv

FDUyyyy

FDUzzzz

LAUXxxxx

(*)

(*)Marke

r

Marker

Marker

FDUnnnn

Marker Setup

Detour Setup

(*) Those FDUs must be declared

with the “Stop Marking” option

ticked.

Line 10

Line 20

Line 30

Low Box Type Low S.N. Low

Chann NbHigh

Box Type High S.N. High Chann Nb

Stop Marking

FDU-428 uuuu FDU-428 vvvv

FDU-428 yyyy FDU-428 zzzz

109 110 111 112 113 114



4

instance, if it is easier for you to know the position of FDU No. nnnn, you may just as well set the marker on it rather than FDU No. vvvv.

The snaking topology cannot be used in place of any secondary transverse.

Figure 4-43

Logical line mapped with several physical lines

Figure 4-44

The flexibility of channel assignment in the 428XL allows you to split a line into several segments laid out side by side (or group several segments laid out side by side into one logical line). For example, this lets you shorten the receiver spacing without changing the spacing of your FDUs.

Secondary TransverseYES NO

LAUX428

LAUX428

LAUX428

LAUX428

LAUX428

LAUX428

Box Type S. N. Line Name Point No. Marker Incr.

FDU-428 xxxx 10 109 3

FDU-428 yyyy 10 110 3

FDU-428 zzzz 10 111 3

LAUX428 FDU

xxxx

FDUyyyy

FDUzzzz

Marker

Marker

FDUnnnn

Marker Setup

Line 10

Line 10

Line 10

Line 20

Line 20

LAUX428

Marker

LAUX428

LAUX428

LAUX428

109

109 110 111 112 113 114 115



4

In the Marker setup window, set a marker assigning a known FDU to a known receiver position on each segment to be grouped, with the same Line number and the same Marker Increment (chosen to be equal to the number of segments).

When you go to “Field On”, each split line will act as a single line.

Below is an example where three segments are grouped into one logical line (or a line is split into three segments).

Note The segments making up the split line don’t need to be attached to the same LCI board.

Note The Marker position can be chosen elsewhere within each line segment, that is on any FDU belonging in the line segment. For instance, if it is easier for you to know the position of FDU No. nnnn, you may just as well set the marker on it rather than FDU No. zzzz.


LineTest functions

4

Test functionsIn this section:


• Instrument tests (page 110)

• Sensor tests (page 112)

• Seismonitor (page 115)

OverviewYou open this window by selecting Test Setup from the Setup menu. It allows you to create a list of tests to do, choose whether or not to record the results, and specify which channels to test. For Instrument tests, you also have to choose the channel gain and record length.

Figure 4-45

Select the desired test and options. Click Add to enter the test into the list box. Click Apply to activate your changes, then click Go to launch the test or list of tests.

The results appear in the Numeric and/or Graphic view, whichever is selected. To interpret the results of a particular test, see the legend at the

List of tests to be done in sequence


LineTest functions

4

foot of the main window (with the appropriate test selected in the graphic view).

The settings in the Test Setup window are also used for every test you launch with the Go button in the graphic view.

Note For a description of the principle of each test, see 428XL User’s Manual Vol. 3.

Test TypeClick in this field and choose the desired type of test from the option button that pops up.

RecordedChoose this option if you wish to record the acquisition to a test file.

Size of the record: 4 bytes per sample. (Data is not compressed).

TestSample Rate Gain Filter TypeInstrument Sensor

Noise User-selected User-selected User-selected

Distortion User-selected User-selected User-selected

Gain&Phase User-selected User-selected User-selected

CMRR User-selected User-selected User-selected

Crosstalk User-selected User-selected User-selected

Resistance User-selected See Vol. 3 See Vol. 3

Leakage User-selected See Vol. 3 See Vol. 3

Noise User-selected See Vol. 3 See Vol. 3

Tilt See Vol. 3 See Vol. 3 See Vol. 3

Distortion (FDU2S) User-selected See Vol. 3 See Vol. 3


LineTest functions

4

Absolute SpreadThe Absolute Spread list box is used to specify the lines and receiver positions to be tested (e. g. 10: 101-105g1),

IMPORTANT

You have to specify a gain in the Absolute Spread description or else the syntax would not be correct, but in Instrument tests the gain actually used (for seismic and auxiliary channels) is the one selected with the Gain option button in the Test Setup.

Note With a rectangular spread, there is an easier way of specifying the lines and receiver positions to be tested: select the desired units in the graphic view, then choose and start the desired test with the buttons available in the main window. See To select one or more elements (page 72).

Note In Sensor tests, auxiliary channels are not tested (regardless of whether or not they are included in the spread). In Instrument tests, auxiliary channels can be tested (you have to specify a list of aux channels to be tested).

Note After doing an Instrument test, use the Look function.

Note If an overscaling arises during the acquisition of the test signal (in an Instrument or Sensor test), no result is available (N/A) for that test.


LineTest functions

4

Instrument tests

Figure 4-46 Instrument test setup


Note After doing an Instrument test, use the Look function.

Auxiliary DescriptorThe Aux Descr text box is used to specify the auxiliary channels to be tested (with the same gain as seismic channels). Example of description: Pilot,Aux1, etc. The + operator is not allowed.

Use a hyphen to specify more quickly a range of auxiliary channel numbers (e.g. a1-a4 rather than a1,a2,a3,a4).

GainThis option button allows you to choose the preamplifier gain to be used for the Instrument tests.

See the gain code table on page 96.

Record LengthDuration of the acquisition.


LineTest functions

4
Note: For an Instrument Crosstalk test, the minimum length required is 5 s @ 2 ms SR for FDUs, 8 s for DSU3s.
Instrument Noise(Microvolts) During this test, the channel input is shorted via an internal resistor. Geophones are not connected. The gain, filter type and sample rate parameters are user-selected.

Instrument Distortion(dB) During this test, geophones are not connected. The built-in generator of the FDU is used as input to the channel under test. The gain, filter type and sample rate parameters are user-selected.

Instrument Crosstalk(dB) The test includes two sequences: during the first sequence, the test generator applies a sine wave to the test network in each even FDU. The ADC converter in each odd FDU measures the resulting voltage across its own test network. (The test generator in odd FDUs is disabled).

Conversely, during the second test sequence, the test sine wave is fed to each odd FDU and the resulting voltage is measured across the test network in each even FDU.

Note On the plotter, the test sine wave may appear on adjacent channels (on either side of an LAU). See User’s Manual Vol. 3.

Sample rate(ms)

Record length

Minimum (sec.) Maximum

0.25 1

See 428XL User’s Manual Vol. 3 (Specifications).

0.5 2

1 3

2 3

4 3


LineTest functions

4

A minimum test length is required (5 s @ 2 ms SR for FDUs, 8 s for DSU3s).

The gain, filter type and sample rate parameters are user-selected.

Instrument Gain/Phase error(%) This test returns the maximum error in amplitude and phase. Geophones are not connected. The built-in generator of the FDU is used as input to the channel under test. The gain, filter type and sample rate parameters are user-selected.

Common Mode Rejection(dB) During this test, geophones are not connected. The built-in generator of the FDU is used as input to the channel under test. The gain, filter type and sample rate parameters are user-selected.

Sensor testsSensor tests are run automatically when FDUs have no acquisition to perform. The Test Setup window lets you manually launch one or more Sensor tests on the receivers that you specify in the Absolute Spread list box.

Figure 4-47


LineTest functions

4

The fault threshold is adjustable by selecting Survey from the Setup menu, then choosing Sensor (see page 83).

Note Whenever Sensor tests are launched automatically, i. e. whenever you turn on the line power, or when you click on the Look button, or when neither acquisition nor seismonitor is underway (field update mode or Auto Look option), the Sample Rate defaults to 2 ms for Resistance and Leakage tests.


Resistance(ohms) This test allows you to see if geophones are connected. The Sample Rate is user-selected.

Sensor Leakage(Mohms) This test displays the global leakage resistance between the input conductors of the receiver link and the earth. The Sample Rate is user-selected.

NOTE: If the channel Input is left unconnected (or if the resistance connected exceeds 9999 ohm), the Sensor Leakage test is irrelevant. In “field update” mode, if the Resistance value exceeds the specified limit, the Leakage test is not performed, even if it is selected in the Look Properties setup.

Sensor Noise(microvolts) In this test the noise picked by the geophones is measured by performing data acquisition with no Firing Order. The Sample Rate is user-selected.

Tilt(%) The Tilt test is sensitive to a number of faults relating to the sensors. The test results will be affected by anomalies on cutoff frequencies,


LineTest functions

4

damping, sensitivity, distortion (sticking, friction, etc.) and tilt (geophone not properly planted).

Note In “field update” mode, if the Resistance value exceeds the specified limit, the Tilt test is not performed, even if it is selected in the Look Properties setup.

Tilt ModelThe Tilt Model function is used to store a model of the response to a pulse on geophones, from a number of geophone arrays known to be in good repair. The model will be used subsequently in Tilt tests. Because the samples stored are average values, the higher the number of tested channels, the closer the model to the theoretical impulse response.

If several sensor types are associated with the channels selected for the Tilt Model test, a model is computed for each sensor type to be used in further Tilt tests.

In Dual telemetry, separate models are computed for wireline telemetry and radio telemetry.

For any sensor type that is not associated with the channels selected for the Tilt Model test, the corresponding saved model is not modified.

Clicking Go connects the channel input to both the built-in generator and geophones. Then, acquisition is performed and the model is computed by averaging the responses of all the geophones tested.

Sensor DistortionThe Sensor Distortion test is only available for FDU2S channels.


LineTest functions

4

SeismonitorThis window allows you to monitor the input signal on the channels you specify in the Absolute Spread list box.

Figure 4-48

10: 100-500g120: 100-500g130: 100-500g140: 100-500g1


LineThe Form Line setup

4

The Form Line setupIn this section:


• Line Troubleshooting (page 117)

• Network Management (page 119)

GeneralYou open this window by selecting Form Line from the Setup menu.

Figure 4-49

This window is mainly used for:

• Troubleshooting the line, by going step-by-step with line forming;

• Managing the network in case of multi-path layout.

The typical way of using Form Line is as follows: create a specific power on/off command by selecting the desired options as explained below (see Line Troubleshooting on page 117) and clicking on Add. You can save it by clicking on Apply. Then select a command in the list box by clicking on it, and launch it by clicking on Go.

Note After a set of LAUs is powered on/off and channels are identified by Form Line, all functions can be performed, including Sensor and Instrument tests, seismonitor and acquisition.

List of manual power on/power off commmands



4

Also note that field update is not done automatically on a segment powered up by Form Line: click on Look (in the Sensors view) to collect the field update data.

WARNING

All the information stored in the Form Line menu is used at line power-up. This may prevent some LAU ports from being powered up.

Typically, clear Form Line menu entries after you are finished with troubleshooting.

Note If the Form Line menu is not empty as lines are powered up, the spread is formed step by step. The propagation of power from LAU to LAU is slower than in the normal mode even if referenced LAUs are not connected in the spread (due to the fact that power-up propagation is controlled by software rather than hardware). An “M” appears on the readout of the LCI428 line controller (standing for “Manual mode”).

Line TroubleshootingTo investigate a problem on a line segment, you can power down one of the ports of an adjacent LAUL or LAUX, or power up that port and form a number of channels (or all) attached to it. Also, you can gradually power up/down a Transverse. To do that:

1. Use the Serial Number field, and the option button that pops up as you click in the Box Type field, to specify which unit is targeted.

2. From the Orientation option button, choose the port you want to power up or power off.

3. If you want to power up the port, tick the “Enable” option. If you want to form all the channels attached to that port, tick the “All” option, otherwise specify how many channels you want to form in the Channels to Form field.



4

4. Choose the appropriate Speed, depending on which type of channel is attached to that segment: FDU428 channels support both 8 and 16 Mbits/s data rates; FDU408 channels support only the 8 Mbits/s option (see Default Line Data Rate on page 54).

5. Click Add, then Go.

Forming all channelsWith the “All” option in the Channels to Form field, the Form Line function applies the line power to the selected port. All the channels attached to that port are identified and displayed graphically.

If an LAU is connected at the end of that series of channels, it is powered up, identified and displayed graphically too. The line power is not propagated automatically by this LAU; this must be done using the Form Line function.

This allows you to go step-by-step with line power up.

Forming a number of channelsIf you choose to form only a number of channels, then the Form Line function applies the line power to the line and the requested channels are identified and displayed graphically.

If an LAU is connected at the end of the series of channels, it is powered up, but is neither identified nor displayed. In this mode, you cannot power up LAUs beyond the selected LAU.



4

Network Management In case of multi-path layout, it may be interesting to enable/disable some paths to control the data path and make it optimum.

To that end, you can use the Form Line menu as described below to prevent the line or transverse power from being set by some LAUs.

Assuming the configuration below:

Figure 4-50

If the network is powered up without any control in the Form Line setup, the data path may be that of Figure 4-51 or Figure 4-52 (page 120), depending on how hardware line power is relayed.

LAUX428 #21

LAUX428 #11

LAUX #12

LAUX #22Right Transverse

Right

Right

Right

Right



4

Figure 4-51 Data Path 1

Figure 4-52 Data Path 2

In order to enforce the second situation (Data path 2), optimum for data retrieval, enter a command in the Form Line menu to power off the Right port of LAUX22 (as a result the LAUX#12 to LAUX#22 secondary transverse is displayed but not used for data transfer).

LAUX428 #21

LAUX428 #11

LAUX428 #12

LAUX428 #22

LAUX428 #21LAUX428 #11

LAUX428 #12

LAUX428 #22


LineThe Synthetic setup

4

The Synthetic setupThis setup window allows you to create a virtual spread and use a synthetic signal as seismic source energy to take virtual shots. For example, you can take virtual shots on a virtual spread to see if your setup parameters are consistent.

Figure 4-53

1. Use the navigation keys to move the focus point to the left/right or upward/downward, depending on where you would like to insert an element into your virtual spread.

2. Click on the desired icon at the top to choose which object to add.

3. Click on the appropriate add button, depending on which port you wish to connect to. The two buttons that add elements on the Low/High sides also allow you to choose how many elements you want to add. This is an easy way of replicating line segments.

Navigating

Focus point

1

Adding objects3

Selecting an object to add

2



4

Figure 4-54

4. Clicking on any element in your virtual spread causes its description to appear in the upper right corner.

Figure 4-55

The example in Figure 4-56 shows how to connect a Right Transverse with four FDU links in just a few clicks.

Figure 4-56 Example

Add one or more elements on Low

side

Add on Right side

Add one or more elements on High

side

Add on Left side Line (Low) (High)

Transverse (Left) (R

ight)

Click to choose how many to add

Move focus to

Right Trans-verse

Connect an LAUX

Connect an FDU link

Add an FDU link Add two FDU links



4

Synthetic fileIn order to simulate shots, you have to load a file containing the necessary samples to generate the test signal. Use the Browse button to do that.

The synthetic signal file should contain the description of the signals fed to Seismic and Auxiliary channels. Three cases may arise:

• A single synthetic signal is described: the same signal is fed both to Seismic and Auxiliary Channels.

• Two synthetic signals are described: the first one is fed to Seismic channels and the second is fed to Auxiliary channels (used to simulate single-source correlation operations).

• Three synthetic signals are described: the first one is fed to Seismic channels, the second to the first Auxiliary channel, and the third to the other Auxiliary channels (used to simulate dual-source correlation operations).

See also 428XL User’s Manual Vol. 2.

File Syntax• Blank lines and lines beginning with # in the first column are ignored.

• Acquisitions are identified with a text line starting with the character @ (in the first column) followed by a space character and an acquisition number. If there is no @, the signals described are common to all acquisitions.

• Each synthetic signal described begins with an asterisk (*) in the first column.

• The signal is made up of a succession of samples and described with 5 sample values per line, each line starting with the sequential number of the first value in the line (0, 5, 10, 15 etc.), for the sake of better legibility.

• Each sample is described in the form of a signed integer between -8388608 and 8388607. The maximum number of samples is 32000,



4

allowing descriptions of signals with a maximum length of 32000 times the Sample Rate. If the Acquisition Length exceeds the length of the described synthetic signal, then, after the last sample, the signal starts again with the first sample (sequential number 0).

Example With Signals Common To All Acquisitions# Example of file with 3 signals

* Seismic signal with 20 samples

0 0 1 2 3 4

5 5 6 7 8 9

10 10 11 12 13 14

15 15 16 17 18 19

* AUX1 signal with 20 samples

0 0 1 2 3 4

5 5 6 7 8 9

10 10 11 12 13 14

15 15 16 17 18 19

* AUX2 to AUXN signal with 20 samples (N depending on the spread).

0 0 1 2 3 4

5 5 6 7 8 9

10 10 11 12 13 14

15 15 16 17 18 19



4

Example With Different Signals In Two Or More Acquisitions# Example of synthetic file with different signal in two acquisitions.

@ 1


0 0 1 2 3 4

5 5 6 7 8 9

10 10 11 12 13 14

15 15 16 17 18 19

* AUX signal with 20 samples

0 0 1 2 3 4

5 5 6 7 8 9

10 10 11 12 13 14

15 15 16 17 18 19

@ 2


0 50 51 52 53 54

5 55 56 57 58 59

10 60 61 62 63 64

15 65 66 67 68 69

* AUX signal with 20 samples

0 50 51 52 53 54

5 55 56 57 58 59

10 60 61 62 63 64

15 65 66 67 68 69


LineThe Download setup

4

The Download setupTypically, you need to use the Download setup after installing a new release of 428XL software (and patches if any), to update firmware in LCI428 boards and in the remote field electronics deployed. You also have to use this setup window if you connect any unit that does not have the required software version and/or patches.

Figure 4-57

Typically, this setup window should be used as follows:

1. Be sure the 428XL LCI controller is powered up and all remote line interfacing units (LAUX428, LAUL428, etc.) to be upgraded are connected to it. (FDUs and DSUs may be present but they are not involved).

2. Go to On Line in the Config main window and Field Off in the Line main window.

3. Click on the Show Reference Release button. This opens a result window showing the latest software release loaded on the server.



4

The name of the file containing the latest release and patches appears after each type of unit in the result window.

Figure 4-58

4. Click on the Show Units Version button to view the current version of all line interfacing units deployed (i. e. LCI428 boards, and field electronics other than FDUs and DSUs). Check to see if all units have the required software version, revision and patches.

Figure 4-59

5. If all LCI boards have the required software release and patches but you still wish to update them, choose the Force LCI428 Download option in the Download setup window.

LAUX428 428.1.x dwnfile.hci428.V1x

LAUL428 428.1.x dwnfile.hci428.V1x

LAUR 428.1.x dwnfile.hci428.V1x

Name of the file to load

Patch No.ProductVersion No.

428.1.x

LAUX428 #---, version 428.1.x

LAUR #---, version 428.1.x

Serial number Current software version & patch No.



4

6. If all field electronics units have the required software release and patches but you still wish to update them, choose the Force Download option in the Download setup window.

7. If any LCI or field electronics unit does not have the required release and/or patches, or you wish to download the release again anyway, click on the Select Download Files button. This opens a file selection dialog box that automatically takes you to the appropriate directory (lcCommon/work). Choose the dwnfile.hci428.V1x file that was prompted by the Show Reference Release button at step 3 above.

Figure 4-60

8. Click OK. This causes the name of the selected release file to appear in the Download setup window. As a result, the Update LCI428 and Update Spread buttons are enabled.



4

Figure 4-61

9. To update LCI428 boards, click on the Update LCI428 button.

10. To update field electronics, do the following:

- From the Box Type option button, choose which type of unit you want to update, or choose All.

- Either choose the All Boxes option or use the S/N field to specify the Serial Number of a particular unit you want to update.

- Click on the Update Spread button.

WARNING

Update commands will be rejected if the power supply of the targeted remote units is below 10.5 V. The power supply must stay above 10 V until downloading is complete.

After updating LCI428 firmware, you have to go to Off Line / On Line in the Config main window to restart operations.

If you do not update LCI428 firmware, you only have to go to Field On to resume operations.

Software release file to download



4

Note 1: It is alright if you directly download a patched software version, rather than downloading the original release first, then downloading the necessary patches separately.

Note 2: If, instead of the message “Download completed”, you have the message:

Erroneous download ...

WARNING: turning units off now may make them unusable if not

properly downloaded.

Do you want to retry another download before units are turned off

(y / n)?

- If you choose “y”, then the download procedure is restarted, and software is downloaded again to those units that are not properly upgraded. If the above error message (Erroneous download ...) appears again, then choose “n” rather than retrying, and click on the Update LCI428 button again.

- If you choose “n”, then the download procedure is aborted. Check all connections. Go to Off Line then On Line in the Config main window. click on the Update LCI428 button again.

Note 3: A “Battery failure” error message is generated (logged into the “dwnreport.hci428” report file) if the update process is aborted, that is:

- if the power supply of any targeted unit lies below 10.5 V before downloading begins,

- or if the power supply of any targeted unit drops below 10 V during the download process.


Chapter

5 Operation


• The Main Window (page 132)

• The Process Type setup (page 139)

• The Source Point Setup (page 154)

• The Seismic setup (page 158)

• The Source Type setup (page 162)

• The Delay setup (page 168)

• The Noise Editing setup (page 169)

• The Observer’s Comment Type Setup (page 175)

• How to take shots or sweeps (page 176)

• More About Noise Elimination (page 192)

• More About Correlation (page 198)


OperationThe Main Window

5

The Main WindowIn this section:


• The Operation Table (page 133)

• The Active Source view (page 135)

• The Active Acquisition view (page 138)

GeneralThe Operation client window takes care of the list of shots, providing details on those planned, the one in progress, the next to do, and those done if any. It also provides access to shot controls, lets you view the status of the acquisition, and provides information about the progress of it, i. e. ITB, Transmit Error.

Figure 5-1 OPERATION client window

Operation table (planned shots)

Stacked acquisitions within the selected VPShot controls

Click to close view

Resize by dragging border

Click to add view



5

This button allows you to get different views of a table, referred to as The Operation Table (page 133), which contains the main information for the acquisition of the data, and also allows you to select which Source Point to shoot, if necessary.

For details on how you can arrange the views and toolbars as you would like them, see the Hands-on guide (page 22).

You can show or hide columns in tables by right-clicking in any column heading and selecting Customize (see Figure 1-14).

The Setup menu allows you to generate the Operation table. Each source point in the operation table is associated with a “Process Type” that determines how the Impulsive or Vibroseismic signal is processed. In the case of Vibroseismic operations, the Process Type is itself associated with an “Acquisition Type” that determines which sweep signal to use and which fleet should generate it. If stacking is used, the stack order is visible in the “Active Acquisition” view.

For details on the buttons (Go, Stop, etc.), see The Active Source view (page 135).

The Operation Table

Figure 5-2 Operation table

Operation Table

Right-click to choose source

Done

Ready

To do

Available views



5

The Operation Table contains the main information for the acquisition of the data and allows you to select which Source Point to shoot. Different views of that operation table are available (showing all source points, or only those to do, or only those done).

The source operation table is created using The Source Point Setup (page 154) or by importing an SPS file with the Log window.

Resize the main window, if required, so that all the desired columns can be viewed, or use the “Customize” menu (popping up if you right-click on any column heading) to remove unnecessary columns.

The indicators ahead of shot numbers should be interpreted as follows:

Double-clicking on a shot to do in the Operation Table causes a menu to pop up that allows you to choose which source to use to do that shot. Then the system will rely on your settings in The Source Type setup (page 162) to determine which shots will be done with that source.

If all necessary parameters have been set in all main windows, then clicking any row in the table causes the following functions to be performed automatically in succession:

1- Look function.

2- Spread configuration (Line Forming).

3- Seismonitor function.

Indicator Meaning

Shots to do (planned Source Points).

This Source Point has the focus. A Source is assigned to it. The system is ready to send the Firing Order.

This Source Point has the focus, and acquisition is in progress.

Shot suspended (a number of acquisitions remain to do but the focus has gone to another Source Point).

Shot done. The data from this Source Point has been logged.



5

The Active Source viewThe available sources created with The Source Type setup (page 162) appear in this view telling you which Source Point is currently assigned to each source.

Figure 5-3

The indicators ahead of source names should be interpreted as follows:

Go pushbuttonClicking this pushbutton sends the Firing Order. Unless you are using an Impulsive process type, the selected Automation option (Continuous/Discontinuous/Manual) determines the way of launching the first or next acquisition for the Source Point selected in the operation table, (see page 159).

Stop pushbuttonBy clicking on Stop, you stop the progress of the acquisition sequence. You finish the current operation (acquisition or dump). At this point, in Impulsive mode, you may dump the data to the record process. In other

Indicator Meaning

Next shot to do with this source.

Shot to do with this Source. The system is ready to send the Firing Order.

This Source has the focus, and acquisition is in progress.

Source unused until selected with the popup menu available by right-clicking in the list of shots to do.



5

modes, you can choose either to continue the sequence or do again the acquisition or end the sequence, using the three pushbuttons (Go, Cancel, End respectively) prompted:

• by clicking on Go you continue the sequence, i.e. you start over at the acquisition number highlighted in the acquisition table;

• by clicking on Cancel you skip the remaining acquisitions: the data from the incomplete Source Point is discarded but the shot number remains highlighted (i.e. selected) in the table. You only need to click Go to do it again.

• by clicking on End you record the incomplete Source Point without the remaining acquisitions. Then clicking Go will start the next Source Point.

Abort pushbuttonClicking this pushbutton interrupts the current Source Point after the current acquisition is complete. This stops the sequence and opens a dialog box that lets you record the data or cancel the Source Point:

• If you click OK, the current acquisition is recorded to the SEGD file. Then clicking Go will cause the sequence to continue.

• If you click Cancel, the current acquisition is NOT recorded. The Go, Cancel, End buttons are prompted and have the same effect as after clicking Stop.

The Abort pushbutton is legal while waiting for the Time Break.

T. E. indicator(Transmit Errors) That indicator may appear in the Active Source view in the event of transmission incidents on the Lines. Those errors are automatically recovered by the system (the data is successfully transmitted again) and the seismic data is no way affected. This is simply indicative of difficult transmission conditions.



5

ITB indicator

Figure 5-4 Internal Time Break

(Internal Time Break) This indicator appears if the 428XL fails to receive the Time Break within the TB Window. An ITB is generated after the “Time Break Window” following the Firing Order has expired, with an accuracy of +/- 5ms. See TB Window (page 141).

With a Vibroseismic source, ITB is an abortive error. With an impulsive source, at the end of the acquisition the GUI asks you if you want to record the data (click OK) or discard it (click Cancel).

Blaster indicatorIn the case of an impulsive-type source with a SHOTPRO, or SGS, or Boombox, or Macha blaster controller, the Active Source view also includes a “Blaster” indicator along with Uphole and TB fields. During acquisition an ASCII message is received from the blaster box (via the XDEV adapter on the Auxiliary line) containing the Uphole Time and Time Break values.

• Uphole Time The time the pulse from the blast is detected uphole, determined by analysis of the Uphole Geophone signal.

• TB Confirmed Time Break, amount of time that current flow to the blasting cap was greater than 4 amps. The start of current flow is set up to start at Time Break in the Shot Pro Encoder.



5

The Blaster indicator may be:

• red “No Fire” status code received,

• green “All OK” status code received,

• orange No Confirmed Time Break or Uphole Time, or any of the following Warnings:

- Confirmed Time Break received but no Uphole Time.

- Low battery.

- Uphole Geophone resistance not measured or out of tolerance.

- Cap resistance not measured or out of tolerance.

If the message includes position data ($GPGGA message), the Source Point position is viewed in the POSITIONING client window.

The Active Acquisition viewThe acquisitions to stack, defined with The Process Type setup (page 139), appear in this view.

Figure 5-5

The indicators ahead of shot numbers should be interpreted as follows:

Indicator Meaning

Acquisition to do.

Acquisition in progress.

Acquisition done.


OperationThe Process Type setup

5

The Process Type setupIn this section:


• Auxiliary traces (page 144)

• Impulsive type (page 146)

• Impulsive Stack (page 147)

• Correlation Before Stack (page 148)

• Correlation After Stack (page 149)

• Vibroseismic Stack (page 151)

• How to Generate a Process Type (page 152)

General

Figure 5-6

The “Process Type” associated with each shot determines which type of seismic signal to generate (depending on the associated “Acquisition



5

Type”) and which type of processing to perform prior to recording the seismic data acquired.

Standard/AdvancedIn each process type setup window, the “Advanced” option prompts an extra parameter: Refraction Delay (for Impulsive modes) or Listening Time (for Vibroseismic modes).

Most of the parameters available for the different Process Types you can create are described below but only the first three are always required. Refer to the description of each Process Type to see which parameters you need to set up. See also Auxiliary traces (page 144) and How to Generate a Process Type (page 152).

Firing OrderFor the 428XL to transmit the Firing Order and receive the Time Break, you can choose to attach the source controller to an LCI428 interface or to an LAUX428 unit. Use the “Box Type” option to choose which way to use.

In the Serial Nb field, enter the Serial Number of the LCI428 or LAU428 to use.

If you choose the LCI428 option, use the Plug option button to choose which “Blaster” port to use on the LCI428.

Record LengthThe time (seconds) that the data is recorded. In Impulsive modes, this duration determines the acquisition length (i. e. the length of time that the seismic data is recorded into LAU acquisition units).

See also Specifications in 428XL User’s Manual Vol. 3.

Listening TimeThe time (seconds) that the data is recorded (i. e. Record Length), in Vibroseismic modes. The acquisition length in Vibroseismic modes is equal to the sweep length plus the Listening Time. (The acquisition



5

length is the length of time that the seismic data is recorded into LAU acquisition units).

TB WindowThe TB Window is a time interval that starts when the 428XL sends a Firing Order (FO). During the TB Window the 428XL is waiting for the TB from the shooting system. If the TB occurs within that interval then the acquisition starts. If it doesn’t, then the 428XL generates an Internal TB (ITB) and the acquisition starts. In Vibroseismic operations, ITB is an abortive error. In impulsive mode, at the end of acquisition the GUI will ask you if you want to dump the data to the record process.

Note In Radio or Dual telemetry, the TB Window field is used to adjust the delay between the FO and TB in Dynamite operations, or the delay between Early TB and TB.

Note If you are using an LSI, the delay between the Firing Order and the predicted Time Break must be entered in the TB Window field.

Refraction Delay(Allowable range: 0 to 64000 ms, precision 500 ms). This parameter is only available if you choose the “Advanced” option.

The Refraction Delay allows you to insert a delay between the Time Break received by the 428XL and the beginning of the acquisition. Using the Refraction Delay, you can shorten the acquisition length, but this assumes that you know how long it will take for the signal to travel from the shot point to your spread, or else you may lose data.

Acquisition IndexSequential number of each individual acquisition in process types where Stacking is requested.



5

Acquisition TypeType of acquisition, to be chosen from those defined in the Vibrator main window’s Setup menu. This may be from 1 to 32. In each Acquisition Type, the following is specified:

- type of sweep to be performed by the vibrator fleet or fleets to be used,

- pilot signals to be output by the vibrator controller,

- automatic lift and high line pickup options.

Note for VE432 users only: A noise elimination Threshold Type (modulo 16) is automatically associated with each Acquisition Type:

Threshold Type 1 <=> Acq Type 1


... ...



... ...


Output optionThe Output button allows you to select different operations on the processed data. It is used, associated with the Add, Change and Delete buttons, to build the acquisition table.

• None. You have to select it when you don't want to do any operation on the processed data.

• Dump: This allows you to dump the data to the record process and the plotter after processing the acquisition. The memory is cleared afterwards. You need at least one Dump at the end of the table.



5

Correlation withUsed to specify which auxiliary channel is the reference (Pilot) signal for the correlation of seismic channels. For example, enter “Pilot” if you have assigned “Pilot” as label to that channel. See Label (page 91). This will tell the system where the reference signal is physically connected, for correlating the seismic channels with that signal.

Auto Correlation Peak TimeUsed to shift the autocorrelation peak (recorded on two auxiliary traces). Unless a value other than 1 is entered for the “Auto Correlation Peak Time” shift, only one half of the correlation wavelet will be recorded on each of the two auxiliary traces (negative time side of the peak on one trace and positive time side on the other). Theoretically, the autocorrelation wavelet is symmetrical with respect to the correlation peak standing for zero time offset between the correlated signals.

This time shift is applied to the results of cross-correlation and to similarity tests.



5

Auxiliary tracesThe Auxiliaries pane allows you to describe the process that you want to be done on your auxiliary channels and specify which auxiliary traces you want to record.

Figure 5-7

For an auxiliary channel to be correlated with another, use the * operator (e. g. Aux2*Pilot). The system will automatically use the second operand as the reference signal for the correlation operation.

Autocorrelation or cross-correlation will cause two auxiliary traces to be generated (one trace for the positive time side of the correlation peak, and another trace for the negative time side). To specify which auxiliary trace is used to record the positive (negative) time side, append a Plus (Minus) sign to the description of the trace.

The trace index number in the Auxiliaries list box determines how the auxiliary traces will appear in the SEGD file and on your plotter output. (See Figure 5-7 above).

With the example shown in Figure 5-7 on page 144, the 1st auxiliary trace in the SEGD file will record the uncorrelated pilot, the 2nd auxiliary trace (Aux2*Pilot+) will record the positive time side of the correlation peak, whereas the 3rd auxiliary trace (Aux2*Pilot-) will record the negative time side.

3

Auxiliary Trace Number

Auxiliary channels and processing

Aux2*Pilot-

ta1 Pilotta3 Aux2*Pilot-ta2 Aux2*Pilot+

Pilot

1st Aux Trace in SEGD file3rd Aux Trace in SEGD file2nd Aux Trace in SEGD file

Reference for seismic channel correlation



5

Example for a similarity test

Assuming:

- the reference sweep signal is fed to your 1st auxiliary channel and labelled “Pilot”,

- the ground force signal is fed to your 2nd auxiliary channel and labelled “ReturnSweep”,

- the sweep signal shifted by radio delays is fed to your 3rd auxiliary channel and labelled “ReturnPilot”.

Also assuming you want the following signals on your plotter output and in your SEGD file:

- positive time side of the Autocorrelation wavelet on the 1st auxiliary trace,

- uncorrelated pilot on the 2nd auxiliary trace,

- positive time side of the cross-correlation of ReturnSweep with ReturnPilot on the 3rd auxiliary trace.

Then, you have to use the following description in the Auxiliaries pane:

Figure 5-8

ta3

Autocorrelation wavelet on Aux Trace 1

ReturnSweep*ReturnPilot+

ta1 Pilot*Pilot+ta2 Pilotta3 ReturnSweep*ReturnPilot+

Uncorrelated pilot on Aux Trace 2 Cross-correlation of

ReturnSweep with ReturnPilot on Aux Trace 3



5

Impulsive typeThis type of process is intended for traditional impulsive-source operations (e. g. explosive).

Figure 5-9

See also:

• Standard/Advanced (page 140)

• Firing Order (page 140)

• Record Length (page 140)

• TB Window (page 141)

• Refraction Delay (page 141)





5

Impulsive Stack

Figure 5-10

This type of process is used to stack impulsive data (from any kind of impulsive low energy source, e. g. weight drop) before recording it.

For any auxiliary traces to be stacked too, you must have them on Radio telemetry channels, and use the Prestack option.

The Acquisition pane allows you to create a list of acquisitions to stack. On each acquisition in your list, use the Output option to choose whether to record the stacked data (Dump option) or not (None option). You have to choose at least one Dump on the last acquisition.

If you choose the Raw option, then you record the data unprocessed at the end of each acquisition (with no stacking). So at the end of the sequence you will have one record for each individual acquisition and another one for the result from the stacking process.

See also:







5

• Refraction Delay (page 141)

• Acquisition Index (page 141)

• Output option (page 142)



Correlation Before Stack

Figure 5-11

You use this type of process in Vibroseismic operations. As the wording of the option suggests, correlation will be performed before stacking.

The Raw option is used when you want to record each individual acquisition too. In your SEGD file, you get the stacked correlated data and also the raw uncorrelated acquisition data.

You need at least one Dump of data for each correlation source at the end of your table.”D” can be combined with the two sources, for example D1 to dump the stacked result of the acquisition correlated with source 1.

The possible single-source or dual-source combinations are: d1, d2, d1d2.



5

See also:





• Auto Correlation Peak Time (page 143)

• Listening Time (page 140)


• Acquisition Type (page 142)




Correlation After Stack

Figure 5-12

This is another way to work with a vibrator. The first operation consists of stacking the data and, at the end of it, performing a correlation on the stacked data and recording the result.



5

All parameters are the same as with the Correlation Before Stack option. You just have one more column in the description table, to specify the sign to apply to the acquired data. The sign will be applied to the data and the Pilot.


See also:





• Auto Correlation Peak Time (page 143)









5

Vibroseismic Stack

Figure 5-13

With this mode of operation you just do a stack of the acquisitions. As a result you will record uncorrelated data in your SEGD file.

The Acquisition Type is defined, as is the case for all Vibroseismic operation modes, in the Vibrator main window.

The Stack Sign is used to specify the sign to apply to the acquired data.

If you choose the Raw option, then you record the data unprocessed at the end of each acquisition (with no stacking). So at the end of the sequence you will have one record for each individual acquisition and another one for the result from the stacking process.

Like for all Vibroseismic modes you must request a Dump at the end of the acquisition sequence.


See also:







5







How to Generate a Process Type Select Process Type from the Setup menu.

Use the option button at the top of the Process Type Setup window to choose the desired type of processing. As a result the relevant parameters are prompted in the upper pane.

For a process type with multiple acquisitions, build the acquisition table as follows:

• Click in the Acquisition index box and enter the necessary range of rows for your acquisition table. For example, to create 8 rows in one click, enter “1-8” into the index box;

• Select “None” from the “Output” option button,

Figure 5-14

• Click Add,

• For each acquisition in the list box, select the desired “Output” option (Double-click on the desired acquisition number, select the output option, then click Change).

After entering all the parameters to define your Process Type, you only need to enter a process type number and label in the list box at the foot of the window, and click Add then Apply to save the process type.

1-8



5

To view the parameters of any process type, double-click on it in the list box. Then you can make any changes needed and click Change, or Add, or Delete, as required. To save your changes, click Apply.


OperationThe Source Point Setup

5

The Source Point SetupIn this section:

• Source point parameters (page 154)

• To generate a Source Point setup (page 156)

Source point parametersTo open this setup window, select Operation from the Setup menu.

Creating a source point setup consists of generating an “operation table” containing the characteristics of the successive Shot Points planned. When you are loading SPS files to the database in the Log main window, you automatically generate this table. The window below shows an example of operation table. You can use the Log main window to save the table to a file.

Figure 5-15

Shot Id.Shot Point or Vibrated Point sequential number.

Break PointIf you enter “Yes” in the “Break Point” column, for any Shot/VP, then the spread will not be configured automatically for this source point (so that you can skip it if required).



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Source LineSource Point Line Number, adjustable in steps of 0.1 between Lines L and L+1.

Source ReceiverSource Point receiver position Number, adjustable in steps of 0.1 between receiver positions RP and RP+1.

Spread TypeChoose one of the Spread Types defined through the “Absolute” or “Generic” Spread Setup menu, in the “Line” main window.

• With an “Absolute” spread, you have to specify the complete acquisition spread to be used for each and every shot. When you are loading SPS files to the database in the Log main window, you automatically generate an operation table with the Absolute spread.

• A “Generic” spread describes the pattern of active channels. That is helpful if the programming of the spread is done manually and you do not want to change the description every time the spread moves.

SFLSpread First Line: lowest Line Number in the spread; used along with “SFN” to specify the origin of the spread.

• For a generic spread, SFL is entered by the operator.

• For an absolute spread, SFL is automatically computed by the system.

SFNSpread First receiver position Number: lowest Receiver Position in the spread; used along with “SFL” to specify the origin of the spread.

• For a generic spread, SFN is entered by the operator.



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• For an absolute spread, SFN is automatically computed by the system.

Process TypeChoose one of the Process Types defined through the “Process Type” Setup menu in the Operation main window. The “Process Type” you choose will tell the system which type of seismic signal to generate and which type of processing to perform prior to recording the seismic data acquired.

CommentsMay be used to enter a comment for each VP. Such comments are displayed in the Operation table and recorded in the User Header in the SEGD file. If the “User Header” is entered into the list of parameters for an Observer Report or an SPS text file (using the LOG main window), then the comments will also be included in the Observer Report or SPS text file.

Any ASCII character is allowed except double quotation marks (“).

To generate a Source Point setup Select Operation from the Setup menu.

Use “-” and “/” and comma as shortcuts, in combination with the command buttons (Add, Change, Delete, Reverse), to generate your table in a minimum number of steps.

Shortcut with Add button

In Shot/V.P. Id column:

- Inserted between two numbers, those become the limits of the modification, i. e. 1-6 from 1 to 6.

/ No change in cells, or step operator, e. g. 1-6/2 (from 1 to 6 every two, only cells referring to 1, 3 and 5 will be affected.

, Only named cells are affected e. g. 1,3,5,7 (cells 1, 3, 5 and 7 will be affected).



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In all other columns except Comment.

Any changes you make will not take effect until you click the Apply button.

The Reset button works like an undo command. It restores the table as it was before you last clicked on Apply.

- , will give you a syntax error.

/no change if alone; allows values to be incremented or decremented if it follows a number, e. g. 10.00/-0.05 (on each change of row you will do the subtraction -0.05).


OperationThe Seismic setup

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The Seismic setupIn this section:

• Operating Mode (page 158)

• Automation (page 159)

• Look (page 160)

Operating Mode

Figure 5-16

To open this setup window, select Options from the Setup menu. Click on the Operating tab. To enable and save your changes, click Apply.

• Standard: choose this option to work with an Explosive-type source (dynamite, air gun or any other kind of impulsive energy), or with a standard Vibroseismic source (single source or flip-flop dual source).

• Slip-Sweep: this option enables slip-sweep operations (for VE432 users only). See Slip-sweep on page 184.

• VSR: (Vibrator Signal Recording) Selecting VSR enables data retrieval from radio telemetry units used as Aux channels, as soon as the sweep is complete (rather than waiting for the listening time to expire) so that they can be recorded as auxiliary channels in the SEGD file. Correlated shots are only sent to the QC processing tool



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(not recorded). Raw records are only recorded (not sent to the QC processing tool).

Automation

Figure 5-17

To open this setup window, select Options from the Setup menu.Click on the Operating tab. To enable and save your changes, click Apply.

With a Vibroseismic source or Stacked Impulsive source, the progress of the acquisitions depends on which Automation option you choose. (With an Impulsive source, the automation option is of no effect).

ContinuousYou are in automatic mode. That means, if you don't have any problem during acquisitions, you click Go and you are able to shoot consecutively the SPs or VPs defined in the Operation Table, respecting the operator-selected delay between acquisitions and SP/VPs, without any further action until the next Break Point (if any) is encountered.

You can click Stop to stop the sequence on completion of the current operation (acquisition or dump) and click Go to resume the sequence.

Note 1: Whenever a new field unit is laid out, it does not appear in the Line main window’s topographic view until the spread is formed again. If the spread remains the same for consecutive shots (VPs) in



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continuous mode, no spread forming is performed, so any new unit laid out will not be visible unless you program a Look between VPs (see Look on page 160). If any Sensor tests are selected in the Look setup menu, they are performed too.

DiscontinuousYou will do the entire shot point or VP sequence with the specified delays between acquisitions, and you have to click Go for the next shot point or VP.

The delay between VPs is not used.

You can click Stop to stop the sequence on completion of the current operation (acquisition or dump) and click Go to resume the sequence.

ManualEach acquisition within each shot point must be started manually, by clicking the Go pushbutton. The Delays Between Acquisitions and Between VPs are not used.

Look

Figure 5-18

To open this setup window, select Options from the Setup menu. Click on the Look tab. To enable and save your changes, click Apply.

Recurrence every n VPs



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This Seismic Setup is used for automation of Look and Sensor tests between shot points.

• The AutoLook option is used to enable or disable automatic performance of a Look function between shot points. Tick this option to select the Automatic mode, untick it for the Manual mode (meaning that you will have to click on the Look button in the Line main window).

• Every: This field is used to specify the recurrence rate of the Look function if AutoLook is enabled. The selected tests will automatically be launched after completing the number of shot points specified in this field.

• With Tests: These buttons allow you to choose one or more Sensor tests to be performed by the Look function, in Automatic or Manual mode.

The Resistance and Tilt tests are done jointly: running either of them also runs the other but, unless its button is activated the results from the other test are not used.

Note If AutoLook is used, the acquisition cycle time is lengthened by 0.5 second, plus the time that each test requested takes to execute, that is:

- plus 1.5 s. if you select the Resistance and/or Tilt test;

- plus 1.5 s. if you select a Leakage test.

Note On a line segment including an LSI, the AutoLook function is disabled: to see new FDUs, you must use manual Look in that case.

Note The tests selected in the Look setup use the Gain code selected in the Line main window’s Test setup. If DSUs are used, it is important to see if the Gain selected in the Test setup is the same as that used in the production spread (because switching the gain is time-consuming and also because it is preferable to do the Tilt test with the gain used for production). See Instrument tests (page 110).


OperationThe Source Type setup

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The Source Type setupIn this section:

• Sources (page 162)

• Explosive source parameters (page 163)

• Vibroseismic source parameters (page 164)

SourcesSelect Sources from the Setup menu. This setup window is used to assign a name to each available seismic source and determine how the system will select the next shot to do with that source from the operation table.

The Explo option is for all types of impulsive energy (dynamite, air gun, etc.). The Vibro option is for vibroseismic sweeps.

Figure 5-19

After entering all the parameters to define a type of seismic source, you only need to enter a source type number in the Nb field, and click Add then Apply to save the source type.

To view the parameters of any source type, double-click on it in the list box (at the foot of the Setup window). Then you can make any changes needed and click Change, or Add, or Delete, as required. To save your changes, click Apply.



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Explosive source parameters

Figure 5-20

To open this setup window, select Sources from the Setup menu, click on the Explo tab.

LabelUse this field to enter a self-explanatory name that will identify the source in plain (e. g. a shooter’s name).

Shooter NbUse this field to enter the identification number of the source controller.

CommentUse this field to enter a description of the impulsive source in plain if required.

Increment NbThis field is used to specify the increment step to use after a shot is done, to automatically determine which shot should next get the focus in the list of shots to do. Typically the increment step is 1. An increment step other than 1 is especially helpful in multishooter operations.

• With 0 as Increment step, the Shot Number is not incremented after a shot is done, and no new spread is formed.

• With a Increment step other than 0 (a positive or negative integer), the number of the next shot to do is computed accordingly, the focus jumps to that shot, and the new spread is formed.



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Vibroseismic source parametersTo open this setup window, select Sources from the Setup menu and click on the Vibro tab.

Figure 5-21

LabelUse this field to enter a self-explanatory name that will identify the source in plain (e. g. a vibrator leader’s name).

Fleet NbUse this field to enter the identification number of the group of vibrators to use as the source. To determine which vibrators are included in each fleet, use the VE432 window (see Vibrator Fleet on page 298).

Moving: SequentiallyChoose the Sequential option if you wish to take VPs as scheduled in the operation table.

After a VP is done, with this option, the system will use the increment step specified in the“Step” field to determine which VP to do with this source and select it automatically from the list of VPs to do.

If this source is for VPs with multiple acquisitions to stack, you may or may not have to choose the “Work by Acq” option, depending on whether or not you want to shift the fleet’s vibrators after each sweep.



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Moving: RandomlyChoose the Randomly option if you want to allow the Source Points to get the focus in any order (e. g. if you are using a “DSD network”) rather than follow the order determined in the list of shots to do.

If this source is for VPs with multiple acquisitions to stack, you may or may not have to choose the “Work by Acq” option, depending on whether or not you want to shift the fleet’s vibrators after each sweep.

StepThis field is used to specify the increment step to use after a VP is done, if you choose Sequential as Moving option, to automatically determine which VP should next get the focus in the list of VPs to do. Typically the step is 1. An increment step other than 1 is especially helpful for Flip-flop Vibroseismic operations (see Flip-Flop sweeps on page 179).

• With 0 as step value, the Shot Number is not incremented after a VP is done, and no new spread is formed.

• With a step other than 0 (a positive or negative integer), the number of the next VP to do is computed accordingly, the focus jumps to that VP, and the new spread is formed. For an example with a negative step, see Figure 5-30 on page 182.

Work by AcqIf this source is for VPs with multiple acquisitions to stack, you may or may not have to choose the “Work by Acq” option, depending on whether or not you want to shift the fleet’s vibrators after each sweep.

• Do not choose “Work by Acq” if the multiple acquisitions are to be stacked without shifting any vibrator. As a result:

- In the standard mode (no Slip-Sweep), the multiple acquisitions to stack are done in succession, using the operator-selected delay between acquisitions (see The Delay setup on page 168), without interleaving with other VPs.



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- With Slip-Sweep enabled, because acquisitions are stacked with all vibrators at the same place, the vibrator fleet is implicitly Ready at the end of each sweep (unless this is the last sweep within the VP); therefore, it can shake as soon as the Slip Time has expired. As a result, a VP’s acquisitions will interleave with those of other VPs.

• Choose the “Work by Acq” option if the multiple acquisitions to stack require the vibrator fleet to shift after each sweep. As a result:

- In the standard mode (no Slip-Sweep), after a sweep is done, the focus will pass to the next VP determined with the increment “Step” value (that may be a suspended VP with still a number of acquisitions to do). As a result, a VP’s acquisitions will interleave with those of other VPs.

- With Slip-Sweep enabled, the focus may pass to whichever vibrator fleet is ready to shake, if it falls inside the VP grabbing circle, after the Slip Time has expired. As a result, acquisitions can interleave with those of other VPs. For details on the “VP Grabbing Radius”, see page 214.

Note To enable the system to open and suspend two or more VPs, see System scaling on page 33.

The very first time any vibrator fleet is reported ready to shake at a location that falls within the VP grabbing circle around a planned source COG position, that fleet is assigned to the first acquisition for that VP. If the fleet’s position falls within more than one VP grabbing circles, a dialog box pops up so the operator can choose between the eligible VPs. The subsequent acquisitions to stack will be done by the same vibrator fleet when it is next ready to shake within the same circle.

ClusterThis field is used for simultaneous dual-source operations. The Cluster number determines the two fleets to use simultaneously.



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CommentUse this field to enter a description of the vibroseismic source in plain, if required.


OperationThe Delay setup

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The Delay setupTo open this setup window, select Delay from the Setup menu.

Figure 5-22

• “At end of Acq”: use this slider to set the required minimum time between any two successive acquisitions to stack. This delay is not used if the Manual automation option is selected (see Automation on page 159).

• “At end of VP” use this slider to set the required minimum time between any two successive VPs. This delay is only used if the Continuous option is selected and no Break Point is set on the selected VP.

Each delay is selectable from 0.0 to 99.0 seconds in 0.1-second steps.

If the Slip-Sweep Operating Mode (page 158) is enabled, the Delay setup window is used to adjust the Slip Time instead.

Figure 5-23

The Slip Time is used as follows: after a sweep is started, the Firing Order for the next sweep will not be generated until the vibrator fleet is ready and the Slip Time Delay has expired.

The Slip Time Delay should not be shorter than the desired listening time. See Slip-sweep (page 184) for details.


OperationThe Noise Editing setup

5

The Noise Editing setupIn this section:

• Noise editing parameters (page 169)

• Noise editing thresholds (page 173)

Noise editing parametersTo open this setup window, select “Noise Editing” from the Setup menu. To enable and save your changes, click Apply.

Figure 5-24

Prior to any processing, an offset correction operation is performed on each sample:

A k i A k iA k i

nk

n

( , ) ( , )( , )

= −=

∑1 For details about “n”, see Reference

Information in 428XL User’s Manual Vol. 3



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The stack formula is given below as a reminder:

A(k) = kth sample

n = number of samples in the acquisition

i = trace index

p = stack index

s = current stack fold

Noise Editing(see also More About Noise Elimination on page 192).

HistoricalIf you choose this option, then the noise editing function is enabled. Then you must define the set of parameters which are necessary to remove impulsive noise using an historical type of editing.

Diversity StackIf you choose this option, then the Diversity Stack noise elimination function is enabled. For this type of noise elimination, you are not required to enter any parameter, apart from the Low Trace Percentage, Low Trace Value and Nb of Windows.

The energy (E) from each trace is calculated by averaging the squares of the samples (before correlation). Then each sample is multiplied by the inverse of the energy previously computed.

At the end of n sweeps (when the VP is complete) each sample stacked (before or after correlation) is multiplied by the inverse of the sum of the inverses of the energies previously computed.

There's no peak editing function for that type of noise elimination. The Diversity Stack function cannot be used in Stack-Only operation.

A k i A k i pp

s

( , ) ( , , )==

∑1



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OffIf you choose this option, then the noise editing function is disabled, and no parameters need to be defined.

Editing Type

ZeroingIf you choose this option, then any sample equal to or greater than the editing threshold will trigger the process which zeroes the samples over a window length that is selected by the “Zeroing Length” parameter. Linear-variation taper, over a window selected by the “Zeroing Taper Length” parameter, is programmed before and after the zeroed portion in order to prevent discontinuity.

ClippingIf you choose this option, then every sample equal to or greater than the threshold will be clipped to the editing threshold value by the noise editing process.

Nb of Windows(Allowable range: 1 to 64). Number of noise editing windows.

With the noise elimination function activated, the acquisition length may be divided into one or more windows (1 to 64).

With “Diversity Stack” noise elimination and the “Correlation Before Stack” processing option, a single window is used.

Zeroing Taper Length2n (allowable range for n: 0 to 8). This parameter represents the number of samples corresponding to the linear-variation taper length before and after a zeroed window, when the “Zeroing” option is selected for the “Editing type” parameter.



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Zeroing Length(Allowable range: 1 to 500 milliseconds). Zeroing window length when a sample exceeds the editing threshold, when the “Zeroing” option is selected for the “Editing type” parameter.

Threshold Init Value(Selectable from 0 to -132 in 6-dB steps). Initialization value for all noise editing thresholds and threshold types in all windows of every channel, for “Historical” noise elimination.

Low Trace %(Selectable from 0 to 100%). Criterion for deciding whether a channel is “Low”. If the number (in percent) of samples which are below the value specified in the “Low Trace Value” field exceeds the value specified in the “Low Trace %” field, then the trace is reported as “Low”.

If a trace is “Low”, threshold update is not performed at the end of the sweep.

Low Trace Value(Selectable from 0 to -132 in 6-dB steps). Upper limit for “Low” channel detection. If any channel sample is less than or equal to this limit, then the “low channel detection” process is triggered for the corresponding channel.

Noisy Trace %(Selectable from 0 to 100). Criterion for deciding whether a channel is “noisy”. If the number (in percent, computed with respect to the acquisition length) of zeroed or clipped samples exceeds the value specified in the “Noisy Trace %” field, then the trace is considered as noisy.



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The corresponding trace number is simply reported in the observer's log. No further action is taken (i.e.normal threshold updating takes place).

Noise editing thresholdsClicking “Manual” isolates the Noise Editing process from the preceding process stage and enables local functions for the management of noise editing thresholds. As a result, data acquisition will be suspended until you click “Auto”.

Clicking “Auto” connects the Noise Editing process to the preceding process stage and allows data acquisition and processing to be performed.

Figure 5-25

Hold/Var.This button is used to enable or disable automatic updating of noise editing thresholds in the “Historical” noise elimination process.

Choosing “Var.” enables thresholds to be automatically updated.

Choosing “Hold” causes thresholds to remain fixed at the latest value updated before the “Hold” function was selected.

Init.Clicking “Init.” presets all thresholds (64 windows) on all channels on all threshold types (up to 16) to the initialization value entered for the “Historical” noise elimination process.



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LoadClicking “Load” restores the latest noise editing thresholds saved, so that they can be used as initialization values in the next “Historical” noise elimination process.

SaveClicking “Save” saves all current noise editing thresholds so that they can be used at a later date in “Historical” noise elimination.

This command should be used prior to turning the power off or prior to taking a shot with a different geometry which could affect noise editing.

The “Save” command saves:

• the threshold types used after power-on, or after clicking “Init.” or “Load”, until “Save” is next used,

• the traces used in each threshold type,

• and the 64 windows on each trace (unused windows are initialized at the threshold initialization value).


OperationThe Observer’s Comment Type Setup

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The Observer’s Comment Type SetupSelecting Comments from the Setup menu opens this window that allows you to incorporate favourite comments of your own. Using this function, you can easily and faster insert comments into your Obs Log. These comments are not copied to the SEGD file.

Figure 5-26

Any ASCII character is allowed except double quotation marks (“).

Once you have entered a comment in the upper pane, enter a Number and Label in the respective text boxes in the lower pane, and click “Add” (or “Change”, as required) to add the new comment type into the list box.

Click Apply to save your changes.


OperationHow to take shots or sweeps

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How to take shots or sweepsIn this section:

• Blaster shots (page 176)

• VE432 sweeps (page 177)

• Flip-Flop sweeps (page 179)

• Slip-sweep (page 184)

Blaster shots

Shooting system not supplying the Shooter positionIf the shooting system does not supply the position of the blaster, an audio radio channel is required for the shooter to tell you when he is ready to shoot and which Source Point to shoot. If this is the first shot to do with this shooter, you have to right-click on the Source Point in the Operation table and select the shooter from the pop-up menu. As a result, the focus passes to that shooter and Source Point in the Active Source view. Clicking “Go” will send a message to the blaster and launch the acquisition.

After a shot is done, the system uses the operation table and the increment “Step” associated with the Source to determine which shot should next get the focus (appearing in the Active Source view). Then you only need to click “Go” when the shooter says he is ready, unless you want to choose another shot (by clicking) and shooter (by right-clicking) in the operation table.

Shooting system supplying the Shooter position(Not supported yet).



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VE432 sweepsIn Vibroseismic operations, the way the focus passes from a VP to another depends on the options you choose in The Seismic setup (page 158) and The Source Type setup (page 162):

• In the standard mode (no Slip-Sweep, actual vibrator positions not available), the system relies on the Operation Table and on the parameters associated with the source (increment “Step”, “Moving” and “Work by Acq” options) to determine which VP should next get the focus after an acquisition is done. Two sources can be used simultaneously (see Cluster on page 166). Up to four sources can be used alternately (see Flip-Flop sweeps on page 179).

• If Slip-Sweep is enabled but actual vibrator positions are not supplied, the system relies on the Operation Table to determine which VP should next have the focus after an acquisition is done. Stacking is not allowed.

• If actual vibrator positions are supplied, VPs are not necessarily done as scheduled in the Operation Table. When a fleet is ready to shake and its COG lies in the vicinity of a planned source point to be done with that fleet, the system automatically selects and highlights the matching VP in the operation table, regardless of which VP is next scheduled. The “Acquisition Type” associated with the Process Type determines which sweep signal to use. The “Active Acquisition” view lets you see which acquisition is in progress.

Below is a reminder of the available methods of starting sweeps automatically:



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Note (1) In that case, the arrival of the “Ready” status overrides the operator-selected delay.

Note (2) The VE432 “DSD Network” option (see page 267) allows each vibrator to supply its GPS position. When a vibrator fleet is ready (pads down) the leader sends a message containing both the Ready status and the resulting Centre Of Gravity of the source, calculated from the GPS position of each vibrator. This enables the system to automatically select the matching source point in the Operation Table. This way of shooting is referred to as the source “Navigation” shooting mode. If the COG falls outside the programmed circle, then a warning dialog box shows up: click OK if you choose to accept the source position as it is, Cancel otherwise (in that case the system will wait for the next fleet to be ready).

Note (3) In the VE432 main window, a button is associated with each fleet, enabling the Fleet Ready status to be relayed automatically to the Operation window, or retained until you choose to let it go.

Source “Moving” option (Source Type setup menu)

Sequentially Randomly(VE432 DSD network)

Standard Slip-Sweep (VE432)

Navigation Navigation & Slip-Sweep

Sweep start conditions

- Vib. Fleet Ready.Or

- Delay between Acquisitions or VPs expired.

(See Note 1)

Slip Time expired. - Vib. Fleet Ready And

- Source COG matching planned VP.

(See Note 2)

- Vib. Fleet Ready

And - Source COG matching planned VP

And - Slip Time expired.

(See Note 2)



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Flip-Flop sweepsWhat is meant by “Flip-Flop” mode with the 428XL is the use of multiple sources alternately (not only two, but up to four).

Flip-flop with two sourcesA simple textbook example of Source Type setup for flip-flop operations is shown in Figure 5-27 where two sources (Source1 and Source2) are alternately generated by two vibrator fleets (respectively F1 and F2). In this example, no stacking is requested.

Figure 5-27 Typical Flip-Flop, no stacking

With the above settings, if you right-click on VP3 and choose “Start Seismonitor with Vib Source1”, and right-click on VP4 and choose

Source1Source2

Source1Source2

22

3 1 1 Dump

Source1 21

1 3 12 4 1

Source1

Expired delayF2 Ready F2 ReadyF1 Ready

F1 moving to VP5 location

Source2

VP3 (Acq1)

VP4 (Acq1)


VP5 (Acq1)


VP6 (Acq1)



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“Start Seismonitor with Vib Source2”, then the system will do VP3 with fleet #1, VP4 with fleet #2, VP5 with fleet #1, and so on.

In the example shown in Figure 5-28 below, the same scheme is used but two acquisitions are stacked at each VP without shifting the vibrators.

Figure 5-28 Flip-Flop, stacking with no vib shift

With the above settings, if you right-click on VP3 and choose “Start Seismonitor with Vib Source1”, and right-click on VP4 and choose “Start Seismonitor with Vib Source2”, then the system will do two stacked acquisitions for VP3 with fleet #1, and then two stacked

Source1Source2

Source1Source2

22

3 1 2 No Dump

Source1 21

1 3 12 4 1

Source1

Expired delay


Source2

VP3 (Acq1)

3 2 2 Dump

VP3 (Acq2)

VP4 (Acq1)

Expired delay

VP4 (Acq2)

VP5 (Acq1)

Expired delay

F2 Ready

F1 Ready

F1 Ready

Expired delay



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acquisitions for VP4 with fleet #2, two stacked acquisitions for VP5 with fleet #1, and so on.

In the example shown in Figure 5-29 below, the “Work by Acq” option is used. As a result the two acquisitions to stack are not done in succession: while the vibrators are shifting to the location of the second acquisition, the system takes an acquisition for another VP.

Figure 5-29 Flip-Flop with “Work by Acq” option

With the above settings, if you right-click on VP3 and choose “Start Seismonitor with Vib Source1”, and right-click on VP4 and choose “Start Seismonitor with Vib Source2”, then the system will do the first acquisition for VP3 with fleet #1, and then the first acquisition for

Source1Source2

Source1Source2

22

3 1 2 No Dump

Source1 21

1 3 12 4 1

Source1


Source2

VP3 (Acq1)

3 2 2 Dump

VP3 (Acq2)

VP4 (Acq1) VP4 (Acq2)

VP5 (Acq1)

F2 Ready

F1 Ready

Expired delay

F1 shifting

F2 shifting

F2 Ready

VP6 (Acq1)




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VP4 with fleet #2 (while a pause icon appears ahead of VP3), and resume VP3 with fleet #1 (while a pause icon appears ahead of VP4), resume VP4 with fleet #2, and so on and so forth.


Note You can use a positive or negative value in the “Step” field.

In the example in Figure 5-30 below, the two source are moving in opposite directions because a negative “Step” is used for source #2.

Figure 5-30 Negative “Step”

2nd acq. in progress

1st acq. doneTo do with source #2

In progress (source #1)

Negative step

Done (source #2)



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Flip-flop with three or four sourcesThe above simple schemes can be extrapolated to four sources.

Note If you want to use three or four sources with the “Work by Acq” option, you have to use the Administration window to set the Maximum open VP parameter (2 by default) to 3 or 4. See System scaling (page 33).

In the example shown in Figure 5-31 below, the system will do only two VPs out of four because the Step field is set at 4 but only two sources are used. You still have to choose the first VP to do with source #2 (using the right-click popup menu) and that with source #4.

Figure 5-31 Flip-flop, 4 sources, with “Work by Acq” option

Not used

Not used2nd acq. in progress

1st acq. done

Suspended

In progress



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Slip-sweep(For VE432 users only)

Theory of operationUp to four vibrator controllers (VE432 DPGs) can be attached to the system, each capable of controlling up to four vibrator fleets. (The total number of vibrator fleets should not exceed 4, however).

With the slip-sweep option enabled, the system lets a vibrator fleet start sweeping without waiting for the previous fleet's sweep to be completed. The system only waits until a delay specified by the operator has expired (the estimated time for a given frequency in the previous sweep to die out) and lets the next vibrator fleet start sweeping when it is ready, with the appropriate receiver stations activated.

The system cuts the acquisition data flow at the appropriate time-zeroes. The data appear in SEGD files as individual correlated records.

Figure 5-32

NOTE: After the Slip Time has expired and the Firing Order is generated, the time required for the VE432 DPG to send the Time Break depends on the number of T0 codes used to synchronize the vibrators.

With two T0 sync codes, the FO to TB time is about 1.5 s, i. e. T = 2 s approximately. See the T0 Setup in the VE432 DPG main window (page 293).

Fleet 2 sweep

Fleet 3 sweep

Slip Time

Slip Time

Slip Time

Fleet 1 sweep

Slip Time

Slip Time

Fleet 1Ready

Fleet 3Ready

Fleet 2Ready

Fleet 2Ready

Fleet 3Ready

T = time from FO to TB

Fleet 1 sweep

T

T

T

T

T

Fleet 2 sweep



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How to implement slip-sweep1. To enable the Slip-sweep option see The Seismic setup on

page 158.

2. To set the Slip Time, see The Delay setup (page 168).

3. Use the The Acquisition Type setup (page 285) menu in the DPG window to create an Acquisition Type (this determines which type of sweep signal will be generated by the vibrator fleets).

4. Use the Process Type setup menu in the Operation main window to create a Process Type for each fleet.

Figure 5-33

- You must use the Correlation Before Stack option.

- All the Process Types you want to use must include the same list of auxiliary channels to acquire. In the example shown in Figure 5-33, “aux1” and “aux2” should appear in each Process Type to use. Process Type #1, is set to display “aux1*aux1” (autocorrelation of “aux1”) on the third auxiliary trace; Process

Same list of auxiliary channels in all process types

Correlation operation specific to this process

type

Same type for all acquisitions to stack in

this process type

Stacking fold



5

Type #2, can be set to display “aux2*aux2” (autocorrelation of “aux2”) on the third auxiliary trace.

- In each Process Type, use a single Acquisition Type for all the acquisitions to stack.

5. Use the The Source Point Setup (page 154) menu to create a list of VPs and build an Operation Table. All VPs should use the same spread (this is easy to achieve by creating a Superspread). Assign one of the Process Types created at step 4 to each VP, for example (see Figure 5-36):

VP11 Process Type 1

VP12 Process Type 2

VP13 Process Type 1

VP14 Process Type 2

VP15 Process Type 1, etc. .

6. Create a Source name and number for each vibrator fleet to use. See Vibroseismic source parameters (page 164) for details. If you choose Sequential as Moving option, choose the appropriate Step (typically to be equal to the number of fleets used), depending on how VPs are to be taken in sequence in your operation table.

Figure 5-34

7. Start each source by right-clicking on the first VP to do with it (e.g. VP11 in the example shown in Figure 5-35) and choose the appropriate source number from the “Start Seismonitor with Vib Source”popup menu (e. g. source #2).



5
Figure 5-35
Figure 5-36 Slip-Sweep with two sources

With the Navigation option enabled (see The Seismic setup on page 158), Slip-sweep shots are not necessarily taken in the order defined in the Operation Table. Instead, the system automatically selects the planned VP that matches the source location received from the next vibrator fleet leader that becomes ready, regardless of which VP is next scheduled to get the focus in the Operation Table.

Second VP11 acquisition starting with Source #2 before first VP12 acquisition is

complete with Source #3

1st acq. done



5

ExamplesIn the examples shown in Figure 5-37 and Figure 5-38, each fleet can start shaking right after the Slip Time has expired.

Figure 5-37 Slip-sweep with sequentially moving source, no stacking

Figure 5-38 Slip-sweep with sequentially moving source, stacking (2)

Fleet 1


Fleet 2



VP5 (Acq1)

VP6 (Acq1)

Slip Time

Slip Time


Slip Time

Slip Time

Slip Time

Slip Time

VP7 (Acq1)Slip Time

Fleet 1


Fleet 2



VP3 (Acq1)

VP4 (Acq1)

Slip Time

Slip Time


Slip Time

Slip Time

Slip Time

Slip Time

VP3 (Acq2)Slip Time



5

In the example shown in Figure 5-39, each fleet can start shaking when it is Ready and the Slip Time has expired and its COG matches a planned source point to be done with that fleet (see VP Grabbing Radius on page 214), regardless of which VP is next scheduled to get the focus in the Operation table.

Figure 5-39 Slip-sweep, randomly moving source, Navigation option, no stacking

Slip Time


F1 Ready

F2 Ready

F3 Ready

F2 Ready

F1 Ready

F3 Ready

F1 Ready

VP1 (Acq1)Slip Time

Slip Time

Slip Time

Slip Time

Slip Time

VP2 (Acq1) VP4(Acq1)

VP6 (Acq1)




Slip TimeVP6 (Acq1)


Fleet 1

Fleet 2

Fleet 3



5

In the example shown in Figure 5-40, you have to choose the Work by Acq option for each source (see Vibroseismic source parameters on page 164). Each fleet can start shaking when it is Ready and the Slip Time has expired and its COG matches a planned source point to be done with that fleet (see VP Grabbing Radius on page 214), regardless of which VP is next scheduled to get the focus in the Operation table.

Figure 5-40 Slip-sweep with randomly moving source, Navigation option, stacking (2)


Fleet 1

Fleet 2

VP1 (Acq1)Slip Time

F1 Ready

Fleet 3

F1 moves to VP1 second acquisition. location

Slip TimeVP1 (Acq2)

Slip Time Slip Time

Slip Time


VP3 (Acq1)

F3 Ready

F2 Ready

F1 Ready

F2 Ready

F3 Ready

Slip TimeVP4 (Acq1)

F2 moves to VP2 second acquisition. location

Slip TimeVP3 (Acq2)

F1 Ready



5

In the example shown in Figure 5-41, each fleet will start shaking when it is Ready and the Slip Time has expired and its COG matches a planned source point to be done with that fleet (see VP Grabbing Radius on page 214). Because acquisitions are stacked at the same place, the fleet is implicitly Ready at the end of each sweep (unless this is the last sweep within the VP), so it can shake as soon as the Slip Time has expired.

Figure 5-41 Slip-sweep with randomly moving source, Navigation option, stacking (2)

Fleet 1

Fleet 2

VP1 (Acq1)Slip Time


Implicit Ready

Implicit ReadyF1

Ready

Fleet 3

VP1 (Acq2)Slip Time

VP2 (Acq1)Slip Time

F3 Ready

F2 Ready

VP2 (Acq2)Slip Time

VP3 (Acq1)Slip Time

F1 Ready

VP3 (Acq2)Slip Time

VP4 (Acq1)Slip TimeImplicit

Ready


OperationMore About Noise Elimination

5

More About Noise EliminationIn this section:

• “Spike Editing” method (page 192)

• Diversity Stack (page 195)

“Spike Editing” methodThe Spike Editing method removes all samples exceeding a special threshold.

The traces are processed successively in the order generated by the acquisition process. Acquisition is performed line by line (from Low to High receiver positions), starting with the farthest Left line.

The first trace is therefore the farthest in the Low branch, in the farthest Left line.

When the number of traces increases (roll in), the new traces are initialized with the value of the “Threshold Init Value” parameter.

When the number of traces decreases (roll out) it is the last ones which disappear.

Each trace is divided into several time windows whose length is equal to Acquisition Length/Nb of Windows.

The maximum number of windows for each trace is 64.

Each window has its own threshold, expressed as a multiple of 3 dB.

Every acquisition with the same length and energy spreading can be associated with the same threshold type (i.e. if the initial phase only is different). If acquisition types with different lengths or energy levels are used, they must be associated with different threshold types.

There may be up to 16 different threshold types.

Two aspects are to be considered in the processing of a trace: removal of samples exceeding a threshold, and threshold updating.



5

Removal of samples exceeding a thresholdTwo methods can be used:

ZeroingWith this method, any sample greater than or equal to the threshold causes a number of samples to be zeroed.

The number of zeroed samples is specified by “Zeroing Length”, and the zeroing process is brought in and removed gradually, i.e. beginning and ending with a “linear-variation taper”.

The Taper Length is expressed as a number of samples and equal to a power of 2.

ClippingAny sample exceeding the threshold is cut down to the value of the threshold.

Threshold updatingIn each window, the threshold is updated with respect to the highest sample in the window.

Threshold updating is performed at the end of the noise elimination process, using the Range parameter (12 dB) as follows (see also Figure 5-42 on page 194):

Highest sample within D area:If Threshold-3dB-Range > Highest sample, then Threshold is decreased 3dB.

Highest sample within C area:If Thresh -3dB > Highest sample ≥ Thresh-3dB-Range, then Threshold is unchanged.

Highest sample within B area:If Threshold > Highest sample ≥ Threshold-3dB, then Threshold is increased 3 dB.



5

Highest sample within A area:If Highest sample > Thresh and VP's 1st acquisition complete, then Threshold is increased 3 dB.

Figure 5-42

Special casesThreshold updating is not performed:

- if the trace is reported “Low”,

- if the “Hold” option is selected, rather than “Var.” (variable),

- if the trace is “dead” (corrupted).

A trace is “Low” if, before noise elimination, the percentage of samples which are smaller than the specified “Low Trace Value” exceeds the specified “Low Trace %”.

A AAA Thr.

3 dB

(12 dB)

-3 dB B BBB

C CCC

D DDD

Thr.-3dB> max sample≥Thr-3 dB-Range⇒Thr unchanged

Thr.-3dB-Range > max sample

⇒Thr = Thr-3 dB

Thr> max sample ≥ Thr.-3dB

⇒Thr = Thr+3 dBmax sample >Thr.⇒Thr = Thr+3 dB

Range



5

Diversity StackThe Diversity Stack method is only used with “Correlation After Stack” process types.

Each trace is divided into several windows whose length equals:

The maximum number of windows for each trace is 64.

The entire processing is performed before correlation but includes two parts: before stacking and after stacking.

A(k) = kth sample

n = number of samples in the window

i = trace index

j = window index

p = current stack fold

Processing before stackFor each window in a trace, the following computation is performed:

On the first window, the following computation is performed:

On the subsequent windows, a ramp is applied to the samples:

AcquisitionLengthNumberOfWindows----------------------------------------------------

[ ]E i j p

A knk

n

( , , )( )

==

∑2

1

A k( )* 1E i j p, ,( )---------------------



5

• Computation of the ramp increment (S) for a window:

• Processing on the samples:

Assuming the current stack fold is p, when the whole ith trace is computed the following computation is performed on all the E(i,j,p) terms for each window:

Processing after stackAssuming m is the last stacking fold prior to writing to the SEGD file, the following computation is performed:

On the first window, the following computation is performed:

On the subsequent windows, a ramp is applied to the samples:

• Computation of the ramp increment (S) for a window:

S j( )E i j p, ,( ) E i j 1– p, ,( )–

n---------------------------------------------------------=

A k( )E i j 1– p, ,( ) S j( )*k+---------------------------------------------------- where (1 ≤ k ≤ n).

1E i j p, ,( )--------------------- 1

E i j p 1–, ,( )------------------------------+

A k

E i j pp

m( )

( , , )

∗

=∑

11

1



5
• Processing on the samples:
where (1 ≤ k ≤ n).

See also More About Correlation (page 198).

S jE i j p E i j p

np

m

p

m

( )( , , ) ( , , )

=

−

−= =∑ ∑

11

11

11 1

[ ]A k

E i j p

S j k

P

m( )

( , , )

( )∗

−

+ ∗

⎡

⎣

⎢⎢⎢⎢

⎤

⎦

⎥⎥⎥⎥

=∑

11

11


OperationMore About Correlation

5

More About CorrelationIn this section:

• Description (page 198)

• Data Distribution (page 201)

DescriptionCorrelation is achieved in the frequency domain, using the “Fast Fourier Transform” method. It is performed on a set of data whose length is 2n, greater than “Pilot length” or “Sweep length”, whichever is the longest, + “Investigation length”.

The results from the correlation process begin with positive time result data and end with negative time result data.

Correlation may be performed on three types of traces:

• auxiliary traces

• seismic traces

• seismic traces in similarity tests.

Correlation of auxiliary tracesThe following operations are allowed on an auxiliary trace:

• Autocorrelation (e.g. aux1*aux1)

• Cross-correlation (e.g. aux2*aux1)

• Stack (e.g. aux3)

For Autocorrelation or Cross-correlation, the second term in the expression of the correlation operation stands for the reference wavelet.

Autocorrelation and cross-correlationAutocorrelation and crosscorrelation processings are identical. The results consist of two traces: one for negative time shifts, one for positive time shifts. Correlation is performed as follows:



5

• A direct Fast Fourier Transform is performed on the “pilot” auxiliary trace, with this trace as real part and 0 as imaginary part.

• A direct Fast Fourier Transform is performed on the “operand” auxiliary trace, with this trace as real part and 0 as imaginary part.

• A complex multiplication is performed of the result from the “operand” auxiliary trace FFT by the result from the “pilot” auxiliary trace FFT.

• A reverse Fast Fourier transform is performed on the result from the complex multiplication.

StackNo correlation is performed on an auxiliary trace. Only stacking is performed.

When two pilots are used, the results from auxiliary traces are located in the two records.

The order in which the result traces are written in SEGD files agrees with the order of sequences in the description of the processings to be done.

Correlation of seismic tracesThe following operations are allowed on seismic traces:

• Correlation with one auxiliary trace (1 Pilot);

• Correlation with two auxiliary traces (2 simultaneous Pilots).

Correlation with 1 PilotEach correlated trace yields a single result trace (positive time).

Correlation with 2 PilotsEach correlated trace yields two result traces:

• 1 trace results from correlation with the first pilot (positive time).

• 1 trace results from correlation with the second pilot (positive time).



5

This gives rise to two records with the same trace count.

If a trace is “dead”, then all its samples are zeroed.

Correlation is performed as follows:

• A direct Fast Fourier Transform is performed on the “Pilot” auxiliary trace, with this trace as real part and 0 as imaginary part.

• A direct Fast Fourier Transform is performed on two seismic traces with one seismic trace as real part and the other seismic trace as imaginary part.

• A complex multiplication is performed of the FFT result from the 2 seismic traces by the FFT result from the pilot auxiliary trace.

• A reverse Fast Fourier Transform is performed on the result from the complex multiplication.



5

Data Distribution

Pilot length < Sweep length

Seismic trace correlation

Figure 5-43

Auxiliary trace correlation

Figure 5-44

Raw data or trace stacking

Figure 5-45

2 n

2n

0

0

0

0

Pilot length

Aux trace (Pilot)

seismic trace(sweep length + record length)

sweep length + record length

0

0 0

0

2 n

2 n Pilot length

Aux trace (Pilot)

Aux. trace


0

0 Pilot length

Aux trace





5

Pilot length = Sweep length


Figure 5-46


Figure 5-47


Figure 5-48

2 n

2 n

0

0

0

0

Pilot length

Aux trace (Pilot)



0

0 0

0

2 n

2 n Pilot length

Aux trace (Pilot)

Aux. trace


0

0 Pilot length

Aux trace





5

Pilot length > Sweep length and ≤ (Sweep length + Record length)


Figure 5-49


Figure 5-50


Figure 5-51

2 n

2 n

0

0

0 0

0

Pilot length

Aux trace (Pilot)



0

0 0

0

2 n

2 n Pilot length

Aux trace (Pilot)

Aux. trace


0

0

0

0 Pilot length

Aux trace





5

Pilot length > Sweep length and > (Sweep length + Record length)


Figure 5-52


Figure 5-53


Figure 5-54

2 n

2 n

0

0

0 0

0

Pilot length

Aux trace (Pilot)


Pilot length + record length

0

0 0

0

2 n

2 n Pilot length

Aux trace (Pilot)

Aux. trace


0

0

0

0 Pilot length

Aux trace




Chapter

6 Positioning




• The layer manager (page 222)

• The geographical view (page 218)

• The Tracking view (page 231)

• Vehicles (page 236)

• The Alert system (page 241)

• Working with the GIS (page 247)


PositioningThe main window

6

The main windowTo open the Positioning main window, click on this icon in the launcher bar.

The Positioning client window makes use of Receiver and Source SPS files to generate an image of the spread, possibly superimposed on a background map, so that you can monitor the progress of a seismic crew in real time.

Vibrator status messages (including vibrator positions if each vibrator is equipped with a radiopositioning receiver) are used to display actual source positions which are compared to expected ones for the purpose of Quality Control.

The following major features are available:

• Geographical view or your survey, based on the set of source points and receiver points in it (see SPS files on page 329).

• Viewing the progress of acquisitions in real time with:

- graphical display of the actual position of vibrators;

- calculation of the actual Centre of Gravity of the source, and comparison with the planned point;

- predicted position of vibrators, depending on the stacking fold.

• Launching a shot by simply dragging and dropping a source onto a source point in the graphical view.

• Real-time tracking of vehicles equipped with an MRU tracking system; broadcasting waypoints to the tracked vehicles.

• Enhancing safety in the crew with a variety of alerts (emergency alarm, vehicle speed, inclusion/exclusion areas, etc.).

• Requesting and building all sorts of reports and/or histograms on any object appearing in the window, by simply clicking on the object in the graphical view.



6

Figure 6-1

The View menu allows you to customize the main window by choosing one or more views to display. For details on how you can arrange the views and toolbars as you would like them, see the Hands-on guide (page 22).

A GIS (Geographical Information System) is used to display the geographical data in a multi-layer manner. The left-hand pane in the Geographical view (Figure 6-1) reflects the structure of the GIS and serves as a plot layer manager window for the different drawing layers that can be plotted in the right-hand pane. See The layer manager (page 222).



6

The following information is displayed in the locator bar at the foot of the window:

• Coordinates (Easting, Northing, Elevation) of the position the mouse is pointing to, within the graphical view.

• Line number of the Line on which the mouse pointer is resting.

• Point Nb number of the point on which the mouse pointer is resting.

• Distance Distance between two points selected with the mouse.

WARNING

If a background map is loaded but not viewed, the map is still active and used as reference for Source and/or Receiver position views. (The map remains active until you unload it).


PositioningThe Setup menu

6


• The Datum Type setup window (page 209)

• The Projection Type setup window (page 211)

• Quality Warning setup window (page 213)

• The Vehicle Identity setup (page 216)

The Datum Type setup window

Figure 6-2



6

In order to locate a point on the earth you need to know its coordinates and the geodetic DATUM.

To open this setup window, select Geodetic from the Setup menu and click on the Datum Type tab. This setup allows you to display Datum parameters and make any changes needed.

A Datum is defined with the following parameters:

• Datum Spheroid: datum name.

• Semi-major Axis: allowable range 0.001 to 99999999.999 m.

• Inverse Flattening: allowable range 0.0000001 to 9999.9999999.

• Shift Dx: allowable range -9999.999 to 9999.999 m.

• Shift Dy: allowable range -9999.999 to 9999.999 m.

• Shift Dz: allowable range -9999.999 to 9999.999 m.

• Shift Rx: allowable range -99.999 to 99.999 s.

• Shift Ry: allowable range -99.999 to 99.999 s.

• Shift Rz: allowable range -99.999 to 99.999 s.

• Datum Scale Factor: allowable range 0.0000000001 to 1.1000000000.

After entering all the parameters to define a Datum, you only need to enter an identification number in the Nb field (allowable range 1 to 16), and click Add then Apply to save the Datum type.

To view the parameters of any Datum type, double-click on it in the list box (at the foot of the Setup window). Then you can make any changes needed and click Change, or Add, or Delete, as required. To save your changes, click Apply.

Note You can define up to 16 Datum types.

You select the Datum type to use through the Projection Type Setup.



6

The Projection Type setup windowYour GPS receivers normally output GPGGA-type messages (Latitude, Longitude, Altitude above the ellipsoid). The computer has to perform a projection so that the position can be pinpointed on your survey map.

Figure 6-3

To open the Projection setup window, select Geodetic from the Setup menu, then click on the Projection Type tab. This setup allows you to display the projection parameters and make any changes needed.



6

The option button at the top (Currently used Projection Type) allows you to choose which projection type to use.

A Projection Type is defined with the following parameters:

• Datum Type: This option button is used to choose which Datum Type to attach to the projection. You define Datum types through The Datum Type setup window (page 209).

• Other parameters depending on the kind of projection used (Lambert, UTM, etc.).

For angular parameters (Central Meridian, Latitude origin, Reference Latitude, North Latitude, South Latitude, Skew Angle) the format is:

dddmmss.ss

(Degrees, Minutes, Seconds with two decimal places).

Examples:

Latitude North 16° 4' 56.24" = 160456.24

South 16° 4' 56.24" = -160456.24

Longitude East 120° 1' 2.3" = 1200102.3

West 120° 1' 2.3" = -1200102.3

• Elevation referenced to (Geoidal Model/Local Ellipsoidal Model): This option button allows you to choose the reference for the Surface Elevation parameter which may appear in log files (APS, SPS, COG, etc.):

- Geoidal Model: with this option, Surface Elevation is equal to

geoidal altitude + altitude correction

- Local Ellipsoidal Model: with this option, Surface Elevation is equal to:

(geoidal altitude + geoidal separation) + altitude correction

Note The geoidal altitude and separation are extracted from $GPGGA messages.



6

After entering all the parameters to define a Projection, you only need to enter an identification number in the Nb field (allowable range 1 to 16), and click Add then Apply to save the Projection type.

To view the parameters of any Projection type, double-click on it in the list box (at the foot of the Setup window). Then you can make any changes needed and click Change, or Add, or Delete, as required. To save your changes, click Apply.

Note You can define up to 16 Projection types.

Quality Warning setup windowSelecting “Source Quality Warning” from the “Setup” menu opens a dialog box used to enter alert thresholds for source positions.

Figure 6-4

Click Apply to save and enable your changes.

COG Radius Threshold(Allowable range: 1. to 99.9 m). Determines the allowable area for the actual COG around the planned source position. Each planned source position in the graphic display is represented by a (blue) tolerance circle the size of which is proportional to the “COG Radius Threshold” parameter.

The actual Centre Of Gravity of the source is computed from the GPS positions contained in the status messages transmitted by the vibrators making up the source.



6

VP Grabbing Radius(Allowable range: 1. to 99.9 m). Used in Navigation mode to determine the eligible VP, if stacking is used and the fleet has to move after each sweep within the VP. This parameter determines a larger circle around the source COG tolerance circle. When a vibrator fleet is located within the VP grabbing circle and ready to shake, the system chooses the matching VP from the list of VPs in the Operation main window. See VE432 sweeps (page 177).

Figure 6-5

- For each acquisition, individual vibrator positions as well as the fleet’s COG are displayed in the main window.

- The estimated COG of the VP is computed again at each acquisition, using the actual COG of the acquisitions already done and the predicted COG for the acquisitions still to be done.

- After the VP is completed, the information about the acquisition is replaced by the actual COG of the VP.

Note With no stacking (i. e. a single acquisition per VP), the “VP Grabbing Radius” should be set to be equal to the “COG Radius Threshold”. Otherwise, if the COG falls outside the COG Radius Threshold circle but within the VP Grabbing circle, the operator will not be warned of the COG radial error when the Ready message appears but only after the VP is done (the alert threshold associated with the Ready message is determined by the largest of the two circles).

COG

Acq1

Acq2

COG Radius threshold

VP Grabbing Radius

Planned source Centre Of Gravity

COG tolerance circle

VP grabbing circle



6

Vib Position Accuracy Threshold(Allowable range: 0.0 to 99.9 m). This field is used to specify the maximum allowable uncertainty on the GPS positions of the vibrators, i.e. the maximum allowable value of the Horizontal Dilution Of Precision contained in the status messages transmitted by the vibrators making up the source. If the HDOP exceeds the Threshold specified in this field, then the position is regarded as “inaccurate”.

About the vibrator position Quality ControlThe quality of a vibrator's position is determined using the quality figure contained in field No. 6 in the $GPGGA message from the GPS receiver in the vibrator. The quality figure may assume values from 0 to 8. (See NMEA standard version 2.30).

The position is regarded as:

• “missing” for values 0, 6, 7, 8,

• “natural” (straight GPS) for 1,

• “actual” for values 2, 3, 4, 5.

The Horizontal Dilution Of Precision (HDOP) is taken from field No. 8 in the $GPGGA message.



6

The Vehicle Identity setupTo open this setup window, select Vehicle Ident from the Setup menu. This setup allows you to specify which vehicles to track in the Positioning window and, for each of them, specify the maximum allowable speed.

Figure 6-6

Nb(Allowable range: 1 to 50). Identity number of a vehicle, defined when you configure the MRU for the vehicle. (See MRU User's Manual).

NameLabel you wish to assign to the vehicle identified in the Nb text box.

Max SpeedDetermines the upper limit of the scale for colour-mapping the speed in the vehicle’s trackline.

TrackingFor each vehicle in the list box this option button allows you to specify whether or not the vehicle should be tracked in geographical views. (Click in the field, then select the desired option from the button).

If you choose “True”, then MRU messages from that vehicle will be interpreted. If you choose “False”, then the vehicle is not tracked, its



6

MRU messages are rejected and no alarm is raised if that vehicle fails to reply.

First WaypointInitialization value of the individual waypoint counter attached to each vehicle tracked (by default: 1). This determines the waypoint number that will be assigned to the first waypoint transmitted to any vehicle.

For a given vehicle, the waypoint number is incremented (up to 100) each time a waypoint is transmitted to the vehicle. It is reset to the current First Waypoint value in the event of overflow.

If you change the First Waypoint value, the new value will apply to those vehicles which do not have any waypoint yet and those which have a waypoint counter at 100.

To create a Vehicle Identity SetupTo define a new vehicle in the list box, fill in all the fields as required, then click Add.




PositioningThe geographical view

6

The geographical viewIn this section:


• The layer manager (page 222)

• Background (page 223)

• GeoZones (page 225)

• Swath (page 226)

• Miscellaneous (page 228)

• Vehicles (page 229)

• Sources (page 229)

General

Figure 6-7 Geographical view

That is the basic view in the Positioning client window, consisting of:

• a geographical view showing the planned source points and receiver points imported from SPS files, the actual source points (calculated COGs), service vehicles equipped with a tracking (MRU) box, the

Plot pane

Layer manager pane

Graphical Tools

Right-click to view object properties



6

sources (Shooters and/or VE432 fleets) created in the Operation window;

• a layer manager pane containing all the objects that can be viewed.

You can open as many geographical views as you like (using the View menu). Each is independent and has its own layer manager.

Right-clicking on any object in the plot pane and selecting Feature Properties from the menu that pops up opens a secondary window updated in real time, displaying the properties of the object.

Figure 6-8 Report document

• You can use the Export Selected or Export All button to export some or all of those properties. This generates a report document and opens a preview window that allows you to save, print or export the document by choosing whichever output format you like (PDF, XLS, HTML, TXT, etc.) from its File menu.



6

Graphical tools

Figure 6-9 Graphical tools

• Zoom in: To zoom into an area in the plot pane, click on the Zoom in button, position the mouse in one corner of the desired area, press the left mouse button and hold it down, drag the mouse to the opposite corner of the area (this causes a rubber-band box to appear) and release the button. As a result, the region enclosed by the rubber-band box is redrawn within the same view to occupy the entire plot pane.

• Undo zoom: Reverts to the previous zoom factor.

• View All: Zooms out until all objects fit into the plot pane (in one click).

• Zoom locker: Clicking on this button either locks or unlocks the zoom-out factor, depending on whether it is already locked or unlocked. With the zoom locker enabled, all zoom-out clicks will take you back to the zoom factor you were using at the moment you enabled it.

• Panning: Clicking the Panning button causes the mouse pointer to change to a hand when resting in the plot pane. Then you can drag the display in any direction with the mouse.

• Ruler: To read the distance from one point to another picked up in the plot pane, click on the Ruler button, position the mouse on the first point, press the left mouse button and hold it down, drag the mouse to the other point. This draws a straight trackline in between. The distance between the two points is displayed in a tip box on the first

Undo zoom

PanningView All

Rectangular spatial query

Zoom in

Zoom locker

Ruler Circular spatial query



6

point picked up. The latest distance picked up as you release the mouse button is displayed in the Distance field in the locator bar.

Figure 6-10 Ruler

• Rectangular or circular spatial query: Draws a rectangle or circle area over displayed objects. As a result, all visible objects enclosed by the rectangle or circle are grabbed, and a secondary window appears, showing the list of grabbed objects and their properties. Objects in hidden layers, if any, enclosed by the rectangle or circle are ignored.

Figure 6-11 Spatial query

- You can use the Export Selected or Export All button to export some or all of grabbed objects. This opens a dialog box that lets you choose which properties to export.

- Clicking Accept generates a report document and opens a preview window (see Figure 6-8 on page 219) that allows you to save, print or export the document by choosing whichever output

Refreshed as you release mouse button

Tip box

Figure 6-12



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format you like (PDF, XLS, HTML, TXT, etc.) from its File menu.

The layer managerIn the layer manager (left-hand) pane, the available drawing layers are grouped into several folders that you can expand or collapse (Source sets, Vehicles, Miscellaneous elements, Swath, Geographical Zones, Background maps). If any layer is hidden, its name is dimmed. Each layer has a specific popup menu, available by right clicking on it, depending on which commands can be applied to that layer.

Figure 6-13 Layer manager

To show or hide any drawing layer, first expand the appropriate folder, then double-click on the desired layer, or right-click on it and select the appropriate command (Show Layer / Hide Layer) from the menu that pops up.

The Rename Layer command lets you enter whatever name you like in place of the default name.

The Layer Properties command allows you to view and modify the image properties, for example to change the opacity of the background or to enable or disable smoothing.

Double-click to expand/collapse folder

Double-click or right-click to

show/hide layer

Plot pane

Layer manager pane



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The Delete Layer command lets you delete the layer from the layer manager (e. g. to unload a background map), but this does not delete the file from your computer’s disk. Not all layers can be deleted.

The arrangement in the layer manager pane determines the way the layers are stacked (i. e. overprinted) in the plot pane, the bottom folder being plotted on the background and the top folder on the foreground. You can move any layer by dragging it up or down to change the overprinting order. Naturally, you must be aware that a raster file (the background map) will hide any layer placed below it.

BackgroundThe Background folder is dedicated to background images.

Figure 6-14 Background map

The following file types are allowed:

• Geotiff: raster image with a geographical reference.

• DXF: vectorial data.

• Esri Shapefile: A shapefile stores non-topological geometry and attribute information for the spatial features in a data set. The geometry for a feature is stored as a shape comprising a set of vector coordinates. Because shapefiles do not have the processing overhead of a topological data structure, they have advantages over other data sources such as faster drawing speed and edit ability. Shapefiles handle single features that overlap or that are non-contiguous. They also typically require less disk space and are easier to read and write. Shapefiles can support point, line, and area features. Area features are



6

represented as closed loop, double-digitized polygons. Attributes are held in a dBASE® format file. Each attribute record has a one-to-one relationship with the associated shape record.

• Simple Raster file (e. g. jpeg or gif or tif-format file): this type of file has no geographical reference but the system lets you provide one as you load such a file (See ).

Right-clicking on any background layer and choosing Layer Properties from the popup menu opens a dialog that allows you to change the font and colour of labels if any, and adjust the following image attributes.

Figure 6-15 Image properties

OpacityThis slider button controls how much of the background map will show through.

SmoothingThe Optimal option applies appropriate smoothing for pixels not to be visible, depending on the zoom factor. The Never option does not apply any smoothing. The Always option achieves the best smoothing effect but significantly increases the amount of CPU time consumed by your Positioning window.



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GeoZonesYou may wish to be alerted if any tracked vehicle (vibrator equipped with a GPS receiver or other vehicle equipped with a tracking system) leaves the work area, or gets into quicksands or a boggy or no-trespassing area, etc. The system will take care of that, using the inclusion and/or exclusion zones contained in the GeoZones folder to determine the allowable perimeter.

Figure 6-16 Inclusion/Exclusion zones

After you select Create Exclusion Zone or Create Inclusion Zone from the popup menu, the mouse pointer changes to an arrow. Then you can draw a polygon in the plot pane by clicking at each vertex in turn and closing the polygon with a last click at the first vertex. This adds a new item into the GeoZone folder. Right-click on it in the GeoZone folder to rename it as you like.

Create Exclusion ZoneAllows you to define the perimeter of an area that the crew’s vehicles are not allowed to enter. That perimeter is automatically plotted in red.

Create Inclusion ZoneAllows you to define the perimeter of an area that the crew’s vehicles are not allowed to leave. That perimeter is automatically plotted in green.

Right-click Click



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Load from fileAllows you to load a DXF-format file depicting the desired perimeter. Each file you load creates a new item in the GeoZone folder. Only closed curves are interpreted:

• Red closed curves are interpreted as exclusion zones;

• All other closed curves are by default interpreted as inclusion zones.

Other shapes —if any— included in the file are ignored.

SwathFor each swath, a separate layer is automatically created in the Swath folder, showing the source points and receiver points included in the swath.

Figure 6-17 Swath layer

Source pointsEach planned source position (from the Source SPS file) is represented by a blue circle. The size of the circle is proportional to the “COG Radius Threshold” specified through the “Setup” menu.



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Source COG

The COG position is represented by a solid square inside the planned source position blue circle if there is no radial error, or outside of it if there is a radial error that is if the deviation from the planned COG position exceeds the “COG Radius Threshold” specified through the Setup menu.

The solid square denoting the COG may be:

• Green and inside the source blue circle if:

- this is the actual COG position (i.e all vibrator positions have been received),

- and there is no radial error;

• Red and inside the source blue circle if:

- this is the actual COG position (i.e. all vib positions have been received),

- and one or more vib position standard deviations exceed the “Vib Position Accuracy Threshold” (specified in the Setup menu). The COG is therefore regarded as inaccurate.

• Red and outside the source blue circle if:

- this is the actual COG position (i.e. all vib positions have been received),

- but there is a radial error. In that case a warning box shows up, displaying the radial error and the Source Point identification, so that the operator can decide on whether to reposition the vibrators and take the sweep again, or to continue.

• Blank (not shown) if no position is received from one or more vibrators (in the event of a malfunction in the GPS receiver or in the radio link; in that case, no COG is computed).

Figure 6-18



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Note If an “Impulsive” source is used instead of vibrators and the blaster controller returns a position message ($GPGGA) to the recording unit (e. g. with a SHOT PRO blaster) then the shot point position is viewed.

Receiver PointsEach planned receiver position is represented as a yellow + mark.

MiscellaneousThe Misc folder in the layer manager pane contains the icons for the recording unit and the base camp.

Figure 6-19 Miscellaneous objects layer

By default, if the icon file includes a geographical reference, the icon is displayed at its exact location in the geographical view, otherwise the object appears only in the layer manager pane.

You can place the recording unit or base camp icon into the plot pane by dragging and dropping it from the layer manager pane to the plot pane (left-click on it in the layer manager while pressing the Ctrl key, then move the mouse to the desired location in the plot pane and release the mouse button). Likewise you can move the icon within the plot pane by dragging and dropping it where you would like it to appear.

You can place the icon at its exact location by entering its precise coordinates in the Log window (see Editing/saving/loading 428XL parameters on page 327).

Drag and drop to move icon

Recording truck icon



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VehiclesThe Vehicles folder in the layer manager pane contains all the vehicles equipped with a tracking box (MRU). You can monitor the position of those vehicles in real time, show/hide their tracklines and also send waypoints to them by simply dragging and dropping a vehicle’s icon to the desired location.

See Vehicles on page 236 for details.

SourcesThis folder contains all the sources created in the Operation window that you can use to take shots or sweeps.

Figure 6-20 Source layer

A flag (for a vibroseismic source) or human figure (for an impulsive source) icon associated with each source is available above the plot pane.

You can drag a source icon and drop it onto a planned shot point in the plot pane to launch a shot just like a click on Go would do in the Operation window. To do that, left-click on the source icon while pressing the Ctrl key, then move the mouse to the desired planned shot point and release the mouse button.

For example, this allows you to redo a sweep without lifting the vibrator pads. Dragging and dropping the vibroseismic source simulates the Ready signal sent by the fleet’s leader when all its vibrators have their pads down. You must have clicked on Go at least once beforehand in the Operation window. Also, the fleet’s vibrators are assumed

Vibroseismic source

Impulsive source shooter

Drag and drop to launch sweep or shot



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positioned at the shot point, with their pads down. Unless that is already done, you also have to click on the fleet’s button in the VE432 main window to let its Ready status be relayed to the acquisition system.


PositioningThe Tracking view

6

The Tracking viewIn this section:

• Graphical tracking view (page 231)

• Numerical tracking view (page 234)

• More about the estimated COG position (page 234)

Graphical tracking viewIn the source tracking view are all the details on the Vibrated Point: positions of vibrators (crosshair), the planned active Vibrated Point, the predicted COG (orange square, or green if the stacking fold is achieved), and information about the current VP (Acquisition number/stacking fold, Device number, Source Point Line, Source Point Number, Source Point Index).

Figure 6-21

The button in the upper left corner allows you to freeze/unfreeze the view. Preventing the view from being updated may be helpful if you need time to examine details. Since you can open as many tracking views as you like (using the View menu), you can enable updating in another view and still track the active source.

In each view, you can use any of the fleet (flag) buttons available at the top to choose whichever fleet you would like to be tracked in that view. If you do not choose any fleet, then the active source is tracked.

V1

V2V3

Planned

COGFleet

Enable/disable updating

Choose fleet to view



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The tracking view shows the progress of vibrator positions and source positions updated as soon as the status messages are received from the vibrators. The solid square denoting the COG is:

• Orange and inside the source blue circle if:

- this is an estimated COG position (i.e. some vib positions have not yet been received),

- but the estimation does not lead to any radial error.

• Orange and outside the source blue circle if:

- this is an estimated COG position (some vib positions have not yet been received),

- and the estimation leads to a radial error (e.g. a status message is indicating that a vibrator failed to vibrate. Therefore the estimated COG is computed without the position of this vibrator, leading to a radial error).

Note that COG radial errors are reported in the form of messages in the mail pane at the foot of the window.

Figure 6-22

Each planned vibrator position is represented as a + mark which changes from orange (i.e. estimated) to green as the actual position is received. It turns red if the positions standard deviation exceeds the “Vib Position Accuracy Threshold” specified through the “Setup” menu. It is not shown if any of the status codes of the following malfunctions is encountered:

- no sweep

- no status report

- position message error



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- no GPS position samples

The vibrator positions used in the latest acquisition are annotated with the vibrator numbers.

The vibrator positions of those previous source points which are OK (green solid square) are not shown.

Until the status messages are received from all the vibrators making up the source, the theoretical centre of gravity of the source is estimated from the vibrator pattern of the previous source point and represented by a solid orange square. See More about the estimated COG position (page 234). When status messages are received, the COG is shown as explained above for the geographical view.

In “Navigation” mode with a Stack Order more than 1:

- For each acquisition within a VP, individual vibrator positions as well as the fleet’s COG are displayed.

- The estimated COG of the VP is computed again at each acquisition, using the actual COG of the acquisitions already done and the predicted COG for the acquisitions still to be done.

- After the VP is completed, the information about the acquisition is replaced by the actual COG of the VP.

v

Note When you generate the RAW daily Observer Report, at the end of the day, the SPS “Source” file in the database is automatically updated with the actual source COG positions. (You can use the Log main window to save the updated source file to an archival medium).

The Elevation reported is the elevation value contained in the $GPGGA messages from radiopositioning receivers (referenced to the geoidal model).



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Numerical tracking viewYou can monitor one or more vehicles in real time by right-clicking on the vehicle and choosing Numerical Track on from the menu that pops up. This opens a view pane that continually displays:

• The position of the vehicle (Line name and Receiver Point).

• The distance to the nearest line.

• The vehicle’s speed: the line is displayed in red if the vehicle is motionless.

Figure 6-23

More about the estimated COG position

Prediction tableThe planned source positions (represented by blue circles) are known at the outset as they are contained in Source SPS files. On the contrary, the vibrator pattern is not known until all the vib positions of the first complete pattern have been received.

For example, if 2 acquisitions are taken with 4 vibrators then 8 status messages will be received, containing 8 vib positions, which will be used to compute the actual COG but also to set up a prediction table. An example is shown below.

DSD NumberAcquisition

1 2V1 dx11, dy11 dx12, dy12V2 dx21, dy21 dx22, dy22V3 dx31, dy31 dx32, dy32V4 dx41, dy41 dx42, dy42



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The dx,dy values are horizontal and vertical offset distances between each latest known vibrator position and the latest actual COG position (green solid square).

Figure 6-24

Locating the estimated COGFrom the prediction table the dx,dy pair corresponding to the first vibrator which, in the current pattern, supplied its actual position (green + mark) is chosen to locate the estimated COG.

The estimated COG position (orange solid square) is obtained by adding the selected dx,dy pair (from the prediction table) to the actual easting and northing (respectively) received for this vibrator.

Then the remaining dx,dy pairs in the prediction table are used to locate the estimated positions of the other vibrators with respect to the estimated COG.

The estimated vib pattern is represented by orange + marks.

V1.1dx

dy

Latest actual COG

Latest actual vib position


PositioningVehicles

6

VehiclesIn this section:


• Supported vehicle tracking systems (page 237)

• Customizing tracked vehicles (page 239)

• Vehicle trackline and history file (page 240)

Overview

Figure 6-25

Any vehicle equipped with a SERCEL MRU or Racal type tracking unit can send its position —computed by a radio-positioning receiver— and

GPS

GPS

GPS

Tracking

TrackingTracking

Tracking

Recording station (Lab)

Monitoring station (Camp)

Position+AlarmWaypoints+Service messagesService messages


PositioningVehicles

6

status to a base station, and receive waypoints and/or messages from the base station. This requires that the base station be equipped with a tracking box too. For reference information on the necessary communications scheme, see the MRU or Racal User's Manual. See also Supported vehicle tracking systems (page 237).

The base station can be the GUI computer in the recording truck (referred to as “Lab”) or a monitoring station (referred to as “Camp”). On the base station, whether it be a Lab or Camp station, the Positioning client window must be open.

Periodically, each tracked vehicle reports its latest position and status to the base station, which updates the position in the Positioning window’s graphic pane.

Supported vehicle tracking systemsTo track the position of your vibrators and service vehicles, you can use SERCEL MRU boxes or an equivalent type of tracking box from RACAL.

• MRU type: To configure an MRU as Vibrator or Service Vehicle, see the MRU User’s Manual. The message supplied by an MRU includes the position, the type of unit (Vibrator or Service vehicle) and the alarm status if any.

• Racal type: By default a Racal-type tracking box is identified as “Service vehicle”. To identify it as a Vibrator, a serial port must be modified. The message supplied by a Racal tracking box includes the position, the type of unit (Vibrator or Service vehicle) and the alarm status if any, and the type of message encoded as follows (1 character):

- “E”: Alarm (interpreted as “Vehicle + Alarm”).

- “F”: Interpreted as “Vibrator”.

- Other: Interpreted as “Vehicle”.

An option button in the Installation client window on the workstation lets the user choose which type of tracking box to use.


PositioningVehicles

6

The tracking box connects to the computer through a serial line (A- and/or B-port of the computer).

Figure 6-26

A-portThe computer’s A-port:

• Receives the position and alarms from the vehicles.

• Sends waypoints and service messages to the vehicles.

• It is also used to send specific commands to the tracking box. For example, with a Racal tracking box, changing the record unit position sends the command $PASHS,POS (record unit position). A hardware switch is required between the port of the computer and that of the tracking box.

The workstation’s A-port is configured as follows:

• With SERCEL (MRU) tracking boxes: 4800 Bauds, 8 data bits, 2 stops bits, no parity.

• With Racal-type tracking boxes: 9600 Bauds, 8 data bits, 2 stops bits, no parity.

B-portThe computer’s B-port receives services messages exchanged by the Lab and Camp computers.

It is configured as follows:

• With SERCEL (MRU) tracking boxes: 9600 bauds, 8 data bits, 2 stops bits, no parity.

Tracking box

PositionPort A

Port B Service message

Waypoint, Service message

or printer

ComputerPort A

Port B


PositioningVehicles

6

• With Racal-type tracking boxes: 4800 bauds, 8 data bits, 2 stops bits, no parity.

Note If the A-port is used for another link, the B port can be used in place of it for the messages to and from the tracked vehicles. In that case, communications between Lab and Camp computers cannot be handled by the tracking box.

Customizing tracked vehiclesRight-clicking on the Vehicles folder in the layer manager and selecting Add Vehicle Group opens a secondary window that allows you to create vehicle groups and customize the aspect of vehicles in each group.

Figure 6-27

Each time you add a new group, a subfolder is created in the layer manager (hence a sublayer in the plot pane). As a result, you can apply specific actions to the whole sublayer, for example:

- Rename the group;

- Send a request for specific attributes in order to find the matching vehicles (using the name, or GPS identifier number or any other attribute as search criterion);

- Assign a particular icon to the vehicles in the group.

(Name=”Fuel”)

Fuel


PositioningVehicles

6

Vehicle trackline and history fileThe trackline of each vehicle and also the associated alerts are automatically saved to an XML log file on the client computer’s disk (in the Jpos/workspace/history directory) and sorted by julian day. That file can be imported into any viewing tool accepting XML files.

Real-time displayRight-click on the vehicle’s subfolder in the layer manager pane and select “Show trace route” from the menu that pops up.

The trackline is displayed as segments the colour of which depends on the speed of the vehicle.

The speed is mapped with 10 different colours starting from green (standing for the vehicle’s minimum speed) to red (standing for the maximum allowable speed specified in the The Vehicle Identity setup on page 216. A circle appears on the trackline if any alarm is raised.

Playback from history fileSelecting Load History from the File menu allows you to choose a trackline history file and load it to the Backgrounds folder in the layer manager pane. Then the trackline can be displayed like any real-time trackline (with colour-mapped speed and circles on incidents) and shown/hidden like any other background layer.


PositioningThe Alert system

6

The Alert systemYou can set alert conditions on vehicles by using the setup menu or the toolbar, or simply right-clicking on a vehicle.

You are notified of any incident in two ways:

• An audible warning plus a visual effect in the geographical view (an expanding circle around the vehicle that caused the incident). The colour of the expanding circle depends on the type of incident.

• A tip box popping up as you drag the mouse over any vehicle affected by an incident.

To dismiss an incident on a vehicle, either double-click on the vehicle or right-click on it and choose Reset Alert from the menu that pops up. This may or may not let you get rid of the alert, depending on the type of incident.

Incidents are saved together with the trackline (meaning that they will be visible when you play back the trackline).

The following types of incidents are monitored:

• Emergency (page 241)

• GeoZone perimeter (page 242)

• Global alarms (page 243)

• Excess speed (page 245)

EmergencyThe system continually checks for any Emergency alert from the MRU system (an Emergency alarm is automatically raised if a vehicle’s driver pushes the Emergency button on the MRU tracking box). This requires that the Tracking option in the The Vehicle Identity setup (page 216) be set at “True”.

An Emergency alarm immediately causes a dialog box to show up in the Positioning window, with the position of the vehicle at the moment the alarm was raised.



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Figure 6-28

• Clicking the Send Help button automatically sends a waypoint to the nearest three vehicles to that position, allowing for rescue as quickly as possible. (This also dismisses the alert window).

• If the vehicle does not need any help, simply click Reset Alarm when you want to dismiss the alert window.

GeoZone perimeterInclusion/exclusion zones are created by drawing closed curves in geographical views or loading DXF files depicting such zones (see GeoZones on page 225). GeoZones are intended for vehicles equipped with an MRU system, and for all vibrators (with or without an MRU).

A visual alarm is raised (an orange expanding circle around the position of a vehicle), and a GeoZone perimeter incident is reported, if a vehicle or vibrator:

- enters an exclusion area;

- leaves an inclusion area.

The visual alarm disappears when the vehicle gets back to the allowable perimeter, or if you delete the inclusion/exclusion zones affected (or you double-click on the vehicle).

An inclusion/exclusion zone is active (can give rise to incidents) even if hidden.



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Global alarmsAll vehicles and vibrators equipped with an MRU system and for which the Tracking option in The Vehicle Identity setup (page 216) is set at “True” can be checked for the following types of incidents: Emergency, No Reply, No Move, Camp Distance, Lab distance.

The monitoring of all these incidents is optional, except for “Emergency” alarms. On vibrators, “No move” incidents are ignored.

Clicking on this button in the toolbar opens a dialog box that allows you to choose which incidents to monitor and adjust the alert conditions.

Figure 6-29

In the event of an incident on a vehicle, a visual alarm is raised (an orange expanding circle around the vehicle) and the incident is reported in the log file. The visual alarm disappears when the situation goes back to normal (or if you dismiss it by double-clicking on the vehicle).

The type of unit (metres, feet, etc.) for the Distance and Radius fields is determined in the The Projection Type setup window (page 211).

No replyAlerts you if the position of a vehicle fails to be refreshed within the time (seconds) you specify in the Delay field, for instance if no position message is received from the vehicle.



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No moveAlerts you if a vehicle remains at a standstill (i. e. the position is refreshed but remains within the circle determined by the associated Distance field) for the time you specify in the Delay field (seconds). Because of the so-called “noise” on the position, especially with “straight GPS”, two successive positions from a vehicle can be different even though the vehicle doesn’t move. The system will only assume the vehicle is moving if the distance between two successive positions exceeds the distance (metres) you specify in the Distance field.

Camp DistanceAlerts you if the distance from a vehicle to the “Camp” location exceeds the distance (metres) you specify in the associated Radius field (i. e. the position of the vehicle doesn’t fall within the circle determined by that radius around the Camp location).

Lab DistanceAlerts you if the distance from a vehicle to the “Lab” (recording unit) location exceeds the distance (metres) you specify in the associated Radius field (i. e. the position of the vehicle doesn’t fall within the circle determined by that radius around the “Lab” location).



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Excess speedAll vehicles equipped with an MRU system and for which the Tracking option in The Vehicle Identity setup (page 216) is set at “True” can be checked for speed excess.

Right-clicking on any of those vehicles opens a dialog box that allows you to set the speed alert conditions for that vehicle. Therefore, you can set individual speed alert conditions on each vehicle.

Figure 6-30

For each vehicle monitored, the speed is computed as the ratio of the difference between the last two positions received to the difference between the times when they are received.

In the event of an “Excess speed” incident on a vehicle, a visual alarm is raised (an orange expanding circle around the vehicle) and the incident is reported in the log file. The visual alarm disappears when the situation goes back to normal (or if you dismiss it by double-clicking on the vehicle). On vibrators, “Excess speed” incidents are ignored.

Max SpeedTick this option if you want the vehicle to be checked for excess speed. Untick to disable monitoring.

DelayUse this field to specify the desired time interval (seconds) between two speed tests on this vehicle.



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SpeedUse this field to specify the desired speed limit for this vehicle, expressed in km/hr or miles per hour, depending on the type of unit selected (see The Projection Type setup window on page 211).

Additional EffectsUse the options if you want excess speed incidents to open a dialog box and/or generate an audible warning for this vehicle.


PositioningWorking with the GIS

6

Working with the GISIn this section:

• Object labelling (page 247)

• Attribute colour maps (page 248)

• Query builder (page 250)

Object labellingEach object appearing in a geographical view can be annotated with a tag reporting whichever of its attributes you choose. Those tags are updated in real time, and do not overprint one another. The more you zoom in, the more tags are visible.

To create a tag and show or hide it, right-click on the desired folder in the layer manager pane (Source Point, Source Receiver, COG, or Vehicles) and choose Label Properties from the menu that pops up.

In the example below, vehicles have a label displaying the name and speed.

Figure 6-32

Figure 6-31



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Attribute colour mapsA Classifier tool is available for the items contained in the Swath layer (Source Point, Source Receiver, COG).

This allows you to create classes for the different values of an object’s attribute and have them colour-mapped in a geographical view. You can choose the number of classes to create and which colours to use for the colour mapping.

For example, assuming you want to have a colour-map view of the source average distortion (an attribute available on COGs), then:

1. Right-click on the COG folder in the layer manager pane and choose Classifier from the menu that pops up. This opens the Classifier control window.

Figure 6-33

2. From the Feature Property Names option button, choose the attribute to plot (Average Distortion).

3. From the Bins option button, choose the number of classes to create.

4. Click on the Start button and select the desired colour for the lowest value class.

5. Click on the End button and select the desired colour for the highest value class.

6. Click on Preview to view the result in a Histogram window.



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Figure 6-34
7. Click on Apply. As a result, the average distortion is colour-mapped in the COG layer in the geographical view.

Figure 6-35

To remove the colour map effect and go back to the default colour encoding in the geographical view, right-click on the appropriate folder in the layer manager and select “Reset Queries and Classification” from the menu that pops up.

Colour-mapped average distortion in COG layer



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Query builderA Query Builder tool is available for the items contained in the Swath layer (Source Point, Source Receiver, COG).

The Query Builder allows you to build any kind of query on displayed objects on any attributes of an object, with logical operators (Or, And, Not, etc.), and generate professional reports in PDF, HTML, XCELL files, etc.

For example, assuming you want to get the list of COGs with an average distortion greater than 16, then:

1. Right-click on the COG folder in the layer manager pane and choose Build feature query from the menu that pops up. This opens the query builder window for COGs.

Figure 6-36

2. Select the desired attribute from the Property Name list box.

Save and load back your queries as you like.

The items matching your query can be displayed in a geographical view.



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3. Choose the desired operator.

4. Choose the desired value from the Values list box.

5. Click on Add To Query.

6. If you want to preview the items matching your query in a geographical view, click on the Create Selection button.

7. Clicking on the Generate Report button opens a secondary window that lets you choose which attributes to export. Unless you want to include all, untick those you want to discard by clicking in the associated Export Enabled button.

Figure 6-37

8. Clicking Accept generates a report document and opens a preview window (see Figure 6-8 on page 219) that allows you to save, print or export the document by choosing whichever output format you like (PDF, XLS, HTML, TXT, etc.) from its File menu.

Figure 6-38


PositioningBasic Geodesy Glossary

6

Basic Geodesy Glossary• Datum: Datum results from taking an ellipsoid and moving its centre

so the ellipsoid matches the geoid very closely in your area of interest. For example, in Europe, the International ellipsoid is shifted to fit and called ED50 (European Datum 1950).

For the same location, your latitude and longitude are different on different Datums. Since your GPS receivers normally output on WGS84 you need to convert the WGS84 latitude/longitude to a latitude /longitude on whatever Datum you are surveying on. This is done by on-line Datum transformation routines in SERCEL software.

This is why you are required to select the appropriate Datum. See The Projection Type setup window (page 211).

• Ellipsoid: An ellipse which has been rotated about an axis (example: WGS84). The shape of the ellipsoid is chosen to match the geoidal surface as closely as possible.

• Geoid: An equipotential surface (meaning that the pull of gravity is equal everywhere along the surface), approximately corresponding to the Mean Sea Level. A plumb bob always points perpendicular to the geoid, not to centre of the earth.

• Projection: A projection is a representation of a 3 dimensional plane.

In order to make a section of the ellipsoid into a flat surface, you have to stretch some parts of the surface and compress other parts. The amount of compressing/stretching is known as “scale factor”.

The distance you measure in the real world is usually not equal to the distance measured on the projection.


Chapter

7 Export

This chapter describes the Export client window. It includes the following sections:



• The Functions menu (page 259)


ExportThe main window

7

The main windowTo open the Export main window, click on this icon in the launcher bar.

The Export main window is dedicated to the process of exporting your SEGD files to your archiving medium (disk and/or tape drives). The activity of each type of medium is logged in a separate view (Tape, NFS, FTP).

Figure 7-1

The View menu allows you to open a separate view for each type of export target (Tape, NFS server, FTP server), showing a table in which the activity of the export process is logged. For details on how you can arrange the views and toolbars as you would like them, see the Hands-on guide (page 22). You can move and resize columns in tables by right-clicking in any column heading and selecting Customize (see Figure 1-14).

The Functions menu is used for local controls of tape drives.

In the toolbar are indicators showing the status of each device to which the shot files can be exported.


ExportThe Setup menu

7


• The Tape Setup setup (page 255)

• The FTP setup (page 257)

• The NFS setup on page 258

The Tape Setup setupTo enable recording to a tape, you must choose the “Tape Drive” option as “Export Mode” in the Install window.

Selecting Tape Setup from the Setup menu opens a secondary window with the following parameters:

Figure 7-2

Tape Nb(Allowable range: 0 to 9999).

Allows you to specify a reel tape number to be recorded in the header block of the next records. It is automatically incremented after the Burst is written on tape.

Tape Label(16 ASCII characters max.).

Used to enter a user-friendly name for the reel tape #.



7

Files per Tape(Allowable range: 1 to 9999).

Allows you to specify the maximum number of records that may be written to a tape.

Trace BlockingThis option is not available unless you choose the “Advanced” option.

To improve the system cycle time when recording to a tape drive, you can shorten the record time by activating the Trace Blocking option. With that option enabled, several traces are grouped to form a single block limited to the size you choose with the associated option button.

Unless you choose the trace blocking option, the system will record traces to tape as individual blocks separated by a gap.

When you play back any record on the 428XL, the system automatically chooses the appropriate option.



7

The FTP setupTo export your SEGD files to an FTP server attached to the local network, you must choose the “FTP Server” option as “Export Mode” in the Install window.

Selecting FTP Setup from the Setup menu opens a secondary window with the following parameters:

Figure 7-3

• In the Login and Password fields, enter the log-in name and password that the FTP user will use to connect to the FTP server (this account must be created on the FTP server machine). By default, the User Account is userftp (with userftp as Password).

• In the Address field, specify an IP address (172.27.128.xx) for the machine on which FTP server software (e. g. FileZilla supplied on the SERCEL CD-ROM) is installed. For example, you can use 172.27.128.99.

• In the Remote directory field, enter the name of the directory to which the records will be saved on the FTP server machine.

Figure 7-4

172.27.128.2

(172.27.128.x.)

172.27.128.1GUI FileZilla

172.27.128.99

Local network

ObserverFTP user

428XL server



7

The NFS setupThis setup window allows you to specify the IP address of each external disk attached to the system, and the directory to which to save your SEGD files.

Figure 7-5

After connecting an external disk, you have enter the IP address of that disk on the local network, enter the directory path to which to save your SEGD files on that disk, and then click on the Mount button.

The following IP addresses are allowed:

• 172.27.128.41

• 172.27.128.42

• 172.27.128.43

• 172.27.128.44

The Mount (Unmount) button attaches (detaches) the specified remote directory to (from) the file hierarchy of the server computer at a mount point automatically determined by the system.

Note Prior to removing a disk, click on the associated Unmount button. Disks cannot be unmounted while a file is being written.

Figure 7-6

172.27.128.2

(172.27.128.x.)

172.27.128.1GUI

172.27.128.41

Local network

Observer NAS server

428XL server


ExportThe Functions menu

7

The Functions menuIn this section:

• Auto (page 259)

• Tape (page 260)

AutoThis menu is only available if the Manual function mode is activated.

Selecting Auto from the Setup menu opens a secondary window with the following parameters:

Figure 7-7

Data/TBPChoosing “Data” enables the normal export function.

Choosing “TBP” (Tape Bypass) enables the data to be dumped to the plotter (and the eSQC-Pro server if any) without recording to tape or exporting. To change the dump directory, you have to go to “Data”.

SimultIf you choose the “Simultaneous” option and two or more tape drives are attached to the system, then the seismic data is recorded on two drives concurrently (the first two reported “ready”).



7

TapeSelecting Tape functions from the Setup menu opens a secondary window with the following parameters:

Figure 7-8

EOFThis function causes a second End of File to be written after the latest one. (An EOF is automatically written at the end of each record). The second EOF is usually interpreted as the end of the tape. This resets the file count to 0.

Note Two EOF’s in succession are automatically recorded when the end of tape is sensed in the course of a record or when the file count reaches the “Files per Tape” count. If simultaneous recording on two tape drives is selected (see Auto functions menu) then a double EOF is written on both tape drives.

Release

Tape drives are normally locked by the 428XL application, meaning that they are not available to any other application. The Release command allows you to choose a tape drive and release it so that it can be used by another application, e. g. if you want to use the Copy Media utility (See 428XL User’s Manual Vol. 3).

When you want to use the tape drive again, choose Reinit Export from the Commands menu.



7


ExportReading exported files

7

Reading exported filesNAS disk

So long as the disk is attached to the local network, you can copy your SEGD files to a tape by going to OFF Line in the Config window and then using the CopyMedia utility (see 428XL User’s Manual Vol. 3).

After the NAS disk is removed, you can connect it to an Ethernet port on a UNIX workstation and mount the exported (/mnt/raid) directory at the workstation’s mount point, using the command:

mount <Host name or IP address>: /mnt/raid /<mount point>.


Chapter

8 VE432



• The Vibrator Crew setup (page 266)

• The Basic Type setup (page 269)

• The Acquisition Type setup (page 285)

• The Radio Management setup (page 288)

• The QC Limit setup (page 291)

• The QC Choice setup (page 292)

• The T0 Time setup (page 293)

• Functions (page 295)

• Normal acquisition (page 315)


VE432The main window

8

The main windowTo open the VE432 main window, click on this icon in the launcher bar.

This main window serves as the Graphic User Interface for a VE432 vibrator controller (VE432 DPG). For an introduction to the VE432 system and details on what it is able to do, how it works, how to deploy it, see the VE432 Installation and Reference manual.

Figure 8-1

The View menu and the associated toolbar allow you to customize the main window by choosing one or more views to display. Then you can resize your display panes by dragging the desired border.

You can show or hide columns in tables by right-clicking in any column heading and selecting Customize (see Figure 1-14).

The Setups menu and the associated toolbar allow you to customize sweep signals, set parameters for vibrator fleets and adjust QC parameters.

Function toolbar

Setup toolbar Click to show view

Click to close view


VE432The main window

8

The Functions menu and the associated toolbar provide local controls to be used outside of seismic acquisition periods to adjust the parameters of vibrator DSDs.


VE432The Vibrator Crew setup

8

The Vibrator Crew setup

Figure 8-2

The Vibrator Crew setup dialog box allows you to define a seismic crew by specifying the identification number of the vibrators that can be used in that crew, that is the list of vibrator electronics seen by the GUI, and how many vibrator fleets will be available.

To save the crew defined in the list box, click Apply. This updates the status bar under the function buttons in the main window: an indicator appears for each DSD incorporated in the crew, associated with the identification number of the vibrator (e. g. V1, V2, etc.). The indicator is blank until you run the Look and Set DSD or Fleet functions.

Clicking Apply also clears all the vibrators lists in the dialog boxes that will open when you click some of the function buttons (Set DSD, Get DSD, etc.)

As a result, you have to run the Look function to update the vibrators lists.

Clicking Reset instead of Apply reverts to the former settings.

Crew NbThis field is used to enter the crew identification number (1 to 4).



8

A “DPG” can address only one crew. The crew identification number is used to preclude any interference with other crews working nearby.

FleetsButtons used to specify the fleets (i. e. sources) to be used in the crew. For example, activating buttons 1 and 3 will cause two fleets to be available: fleets 1 and 3.

(To specify the vibrators incorporated in each fleet, see Vibrator Fleet (page 298).

TypeFor each item in the list, this option button allows you to choose the type of controller: either a DSD or a Slave DPG.

Using a Master/Slave configuration makes it possible to record more traces without increasing the number of vibrators or to use two recording systems at two distinct places. The DPG in the Slave recording truck needs to be configured with DPG-Slave software. As a result it is seen as a DSD from the Master DPG. The Slave DPG generates a reference pilot signal synchronous with the Time Break. It does not control any DSD.

For more details, see The VE432 DPG Installation & Reference Manual.

IdThis field is used to specify the identification number (1 to 28) of each vibrator (i. e. DSD) available to the crew. After specifying any vibrator number in this field, click the Add button to enter it into the list box.

DSD NetworkThis button is used to specify whether a “DSD network” is implemented and used. If that is the case, each DSD should be equipped with an Ethernet Adapter that makes it possible to implement an Ethernet radio link between the DSDs. As a result, when the DSDs in the fleet are



8

ready for the next sweep, the fleet's leader sends a “Ready” message to the DPG, containing the geographical position of the Centre Of Gravity of the fleet. The COG is viewed in the Positioning main window.


VE432The Basic Type setup

8

The Basic Type setupIn this section:


• Linear (page 271)

• dB/Hz Log, Tn and dB/Octave Log (page 272)

• Pulse (page 277)

• Random (page 278)

• Custom (page 279)

• Compound (page 281)

• Delay (page 282)

• Deboost option (page 282)

• Generating a Basic Type setup (page 284)

OverviewTo open the Basic Type setup window, select “Basic Type” from the Setups menu. Creating a “Basic Type” is the process of describing a basic signal to be used:

- by the DSDs to generate sweeps for the vibroseismic source (vibrator control signal),

- and/or by the DPG to generate up to four “Pilots” to be used as reference signals for the correlation processors.

You can create up to 32 different Basic Types, which can be combined using the Compound option.

Below are the allowable ranges for the entry fields that may appear in the Basic Type setup window.

Start Taper 0 to 32000 ms.

End Taper 0 to 32000 ms.



8

The start and end tapers are used to reduce the side lobes appearing in the correlation function of the sine wave or pulse. (The ratio of the peak amplitude to the side lobes is a measure of the quality of the correlation function).

Initial Phase -180° to +180°.

Amplitude 0 to 100%.

Length 1 to 64 s (only for Random, Custom and Delay type signals).

Ti 2 to 16 values from 0 to 64 s (T1 must be 0).

Tj 2 to 16 values from 0 to 64 s (T1 must be 0).

Ai 2 to 16 values from -40.00 to +40.00 dB.

Aj 2 to 16 values from 0 to 100%.

Fi 2 to 16 values from 1 to 250 Hz in increasing order of frequency.

Frequency 1 to 250 Hz (only for Pulse type).

Each basic signal type can be composed of up to 16 segments (32 for the “dB/Hz Log” and “dB/Octave Log” basic signals).

For details on each basic signal, see below.



8

LinearYou define a Linear-type signal through an analytic description. At the signal start and end times, and possibly at particular times in between, you have to specify:

• the signal frequency (Hz),

• the signal amplitude (% of requested drive level).

Figure 8-3

The Frequency variation vs. time is linear within each frequency segment. Frequency segments are defined as follows:

• The first Ti,Fi pair (T1,F1) specifies the initial frequency hence: T1 = 0 sec., F1 = initial frequency.

• The second Ti,Fi pair specifies the end time of the first segment (T2) and the signal frequency at this time is F2, etc.

You must define at least two Ti,Fi pairs (i.e. one frequency segment).

Amplitude segments are defined as follows:

• The first Tj,Aj pair (T1,A1) specifies the initial amplitude, hence: T1 = 0 sec., A1 = initial amplitude.

Frequency lines

Signal amplitude



8

• The second Tj,Aj pair specifies the end time of the first segment (T2) and the signal amplitude at this time is A2, etc.

Within each amplitude segment, the amplitude variation vs. time is linear.

The last Tj determines the total signal length. You must define at least two Tj,Aj pairs (i.e. one amplitude segment).

Ti and Tj may be different both in number and value but the last Ti and the last Tj must be the same value.

Note See also page 269.

dB/Hz Log, Tn and dB/Octave LogNote: For non-linear sweeps, the slope in dB is the spectrum slope before correlation, that is assuming the slope of the power spectrum is NdB (N being the slope value programmed in the Basic Type setup), the spectrum of autocorrelation will have a 2 × NdB slope.

dB/Hz Log

Figure 8-4

Frequency lines

Signal amplitude



8

You define a LOG-type signal through a spectral description, by specifying;

- the amplitude (dB) of two or more frequency lines in the signal spectrum,

- the signal amplitude (% of requested drive level) at the start and end times and possibly at particular times in between.

The Frequency variation vs. time is logarithmic within each frequency segment. This signal type is used to compensate for the non-linear response of the ground (HF damping).

Each Fi,Ai pair defines a spectrum line at frequency Fi with amplitude Ai. Fi,Ai pairs are listed in the increasing order of frequency. You must define at least two spectrum lines. You can specify up to 32 frequency segments.

Amplitude segments are defined as follows:

• The first Tj,Aj pair (T1,A1) specifies the initial amplitude, hence: T1 = 0 sec., A1 = initial amplitude.

• The second Tj,Aj pair specifies the end time of the first segment (T2) and the signal amplitude at this time is A2, etc.

Within each amplitude segment, the amplitude variation is linear.

You must define at least two Tj,Aj pairs (i.e. one amplitude segment). The last Tj determines the total signal length. You can specify up to 32 amplitude segments.

The Frequency is expressed as:

Where:

• SegRa = Sb/Se = 10(-Ra/10)

• Sb = Slope at the start of the log segment.

⎟⎟⎠

⎞⎜⎜⎝

⎛−×+×

⎟⎟⎠

⎞⎜⎜⎝

⎛−

+= )11(1log1log

)(SegRaT

t

SegRa

FbFeFbtFi



8

• Se = Slope at the end of the log segment.

• Fb = Start frequency.

• Fe = End frequency.

• T = Te-Tb = Basic signal length.

• Ra represents the attenuation (in dB) within the signal spectrum.

Example:

Ra= 10 - 5 = 5

SegRa =0.316

Note Choose the Deboost option if the signal is to be used for Deboost-type processing. See Deboost option (page 282).

See also page 269.

Delta dB values

Fi (Hz) Ai (dB)

8 5

80 10



8

dB/Octave Log

Figure 8-5

The Ti,Fi fields are used to specify the frequency at the start time and at the end time (two Ti,Fi pairs are required). A single frequency segment is allowed.

The Tj,Aj fields are used to specify the amplitude (% of requested drive level) at the start time, at the end time and, if required, at particular times in between (at least two Tj,Aj pairs are required). The last Tj determines the total signal length. You can specify up to 32 amplitude segments.

The “Slope dB/Octave” field is used to specify the slope in dB/oct of the signal spectrum (“SdB” in the expression below).


Frequency lines

Signal amplitude

n SdB3

---------- 1+=

Fi t( ) Fbn tT--- Fen Fbn–( )×+

1n---

=



8

Tn

Same as dB/Hz Log type (with no Deboost option), except for the frequency variation which is exponential rather than logarithmic.

Figure 8-6


Frequency lines

Signal amplitude

( )

n

nnn FbFeTtFbtFi

SegRaFbFe

FbFe

n

⎥⎥

⎦

⎤

⎢⎢

⎣

⎡

⎟⎟

⎠

⎞

⎜⎜

⎝

⎛−×+=

−⎟⎠⎞

⎜⎝⎛

⎟⎠⎞

⎜⎝⎛

=

111

)(

loglog

log



8

Pulse

Figure 8-7

Two parameters are needed to define a pulse-type signal:

- a frequency (F) that determines the pulse width (T) as:

T = 1/F

- an amplitude (% of requested drive level).

A 1-second signal is generated, with the pulse peak centred at 0.5 second.

A Pulse-type signal is needed for two purposes:

• Checking the polarity of the devices in the system.

• In operation, pulse reflection from shallow layers of the ground.

0

-0.5

-10 100 200 300 400 500 600 700 800 900 1000

T

Time (ms)



8

Random

Figure 8-8

The “Random” basic signal type allows you to take sweeps that do not generate resonant frequencies (e. g. the resonant frequencies of buildings) and also allows two or more vibration sources to be used simultaneously with minimum interference. The “Random” type generates a Pseudorandom noise signal based on one of the four different polynomial sequences selectable from the “Polynomial” option button:

• 65spoly1: first polynomial with 65535-ms sequence length

• 65spoly2: second polynomial with 65535-ms sequence length

• 8spoly1: first polynomial with 8191-ms sequence length

• 8spoly2: second polynomial with 8191-ms sequence length

The two 8-second polynomial options should only be used with listening times less than 8 seconds. The polynomial sequences have been appropriately designed for minimum cross-correlation residual.

You define a Random-type basic signal by specifying:



8

• the polynomial option,

• the amplitude (dB) of two or more frequency lines in the spectrum,

• the signal length (duration), and start and end tapers.

Frequency segments should be defined as follows:

- The first Fi,Ai pair specifies the initial frequency (F1) and the initial amplitude (A1). F1 must be 5, 7, 10, 14 or 20 Hz.

- The second Fi,Ai pair specifies the frequency (F2) and the amplitude (A2) of the signal at the end of the first segment, etc. You must define at least two Fi,Ai pairs (i.e. one frequency segment).

Note Choose the Deboost option if the signal is to be used for Deboost-type processing.

See also Deboost option (page 282).

Custom

Figure 8-9

To define a “Custom” basic type signal, you just have to specify the name of a file saved on the vibrator electronics PCMCIA interface, containing the description of a customized signal of yours.

Note The system will not check to see if you entered a consistent file name until you run the Set DSD function.



8

NOTE: You don't have to specify the Length (this field will be updated by reading the specified file when you run the Set DSD function).

You have to define the shape of the Custom sweep with a tool of your own, and then create an ASCII, DOS- or UNIX-format file containing the samples required by the VE432.

Comments are allowed, beginning with #.

The sweep should be defined with 2000 samples per second, one sample per line. Each sample should be a floating value in ASCII format, scaled between -1 and +1.

Example #

# Sercel Custom sweep

# file custom1.asc

# 11.03.1999

#

0.0000001 # start taper.

0.0000002

-0.0000001

-0.0000004

...

0.99567

...

0.0000001 # end taper

How to load a Custom sweep file to a DPGAfter creating a Custom sweep file you have to move it to the GUI on the server workstation, via whatever medium is available and appropriate (CD-ROM, etc.). You may put it into the /tmp directory or any directory beginning with /users/ (e. g. /users/428XL/ve432/). The



8

file name should be in DOS format, i. e. 8 characters max for the name, 1 dot, 3 characters max for the extension (e. g. custom1.asc).

Run the toolsVeHci program in the GUI console window on the server workstation. See VE432 DPG Installation & Reference Manual.

Choose option 6 (Load custom file to PCMCIA).

The program will ask for the file name and its path. Then the file is transferred to the DPG. With the reference it receives, the DPG performs the necessary format conversion and stores the result to the PCMCIA card without changing the file name.

For example the /users/428XL/ve432/custom1.asc file will be saved as custom1.asc in the PCMCIA card.

Generate a PCMCIA card containing the custom sweep file for each DSD and each DPG to be used.

Compound

Figure 8-10

The “Compound” basic signal type allows you to create a basic sweep signal composed of a combination of two or more basic types. You just have to enter the number of each of those basic types needed into the Basic Type field and click Add in the upper pane. In the lower pane, enter a new number and label and click Add then Apply.



8

You can use this option to define a signal including a delay time: create a delay type with the desired delay length, using the Delay option, then insert it at the beginning of a “Compound” sweep (i. e. the delay-type signal should be the first in the list).

Note The signals will be generated in the order determined in the list box.

Delay

Figure 8-11

The “Delay” basic signal type uses a single entry field (Length, allowable range 1 to 64 s).

If you wish to delay any basic signal, specify the desired delay time in the “Length” field. In the lower pane, enter a new number and label and click Add then Apply. Then use the “Compound” tab to create a new basic type including that delay. See Compound (page 281).

Deboost optionIf you choose the Deboost option for Log or Random type signals, the 428XL will make the necessary computation for the frequency spectrum shape of the output signals to be the same as that of a linear sweep.



8

Figure 8-12

Note Whether or not the Deboost option is enabled, the VE432 generates the same sweep. This option does not affect the behaviour of the VE432.



8

Generating a Basic Type setupThe “Basic Type” setup window allows you to define up to 32 different basic signal types.

1. Click on the appropriate tab, depending on which mathematical function you wish to use.

2. In the upper pane, set the parameters as required.

3. In the lower pane:

- The list box shows the list of basic signals already defined, if any.

- The “Number“ field is used to enter or display a basic signal type number. Example: “25” refers to basic signal #25 (“bas25” in the list box).

- The “Label“ field is used to enter or display a more user-friendly label for the basic signal type. The default label refers to the mathematical function selected for the basic signal.

- The basic signal # displayed in the “Number” field and defined with the selections made in the upper pane is added into the list box when you click the Add button (unless it is already defined).

If you double-click any basic type in the list box, then its characteristics appear in the upper pane. To make changes, click it in the list box, make the desired changes and click Change or Delete. Clicking Apply saves your changes.

Any changes to the Basic Type currently used will not be effective until you use the “Set DSD“ function to initialize the DSDs.


VE432The Acquisition Type setup

8

The Acquisition Type setup

Figure 8-13

An “Acquisition Type” tells the DSDs selected in a fleet (source) what to do. To define an Acquisition Type you have to specify:

- the Basic signal type to be used by all DSDs,

- the signals (up to four) to be supplied by the DPG through its Analog Pilot outputs, if required (to be used in the correlation process),

- two options for the DSDs (baseplate automatic lift, and synchronization with a picked up power line signal),

- an acquisition number and label.

Note Acquisition Types are used in defining Process Types in the “Operation” window.

The list box shows the list of existing acquisition types. To define a new acquisition type, enter its number in the Acquisition Type field, select the desired options and basic signals, then click Add. To make changes, click it in the list box, make the desired changes and click Change or Delete.

To save the current list of acquisition types, click Apply. (To revert to the former list, click Reset instead).



8

Acquisition Type & LabelThe Acquisition Type field is used to enter an identification number (1 to 32) for the Acquisition Type.

Example of syntax: “25” refers to acquisition type #25.

The Label field is used to enter a label (up to 16 ASCII characters) for the Acquisition Type. A default label is prompted by the system (acq type #) but you can enter a more user-friendly one.

Note A noise elimination Threshold Type (modulo 16) is automatically associated with each Acquisition Type:



... ...



... ...


Basic Type NbWhen you create an Acquisition Type, you specify which Basic (sweep) signal the DSDs should generate. You do that by entering the desired Basic Type number (defined using The Basic Type setup on page 269) into this field.

Pilot Basic NbThe DPG can generate up to four Pilots, available on its “Analog Pilot” outputs, to be used as reference signals for the correlation processor. A Pilot signal is synchronous with the Time Break signal and usually very similar to the fleet's sweep signal. The Pilot signals should be fed to Auxiliary channels on the acquisition system. (See Installation Manual).



8

When you create an Acquisition Type, you specify which Pilots the DPG should generate. You do that by entering the desired Basic Type number (defined using The Basic Type setup on page 269) into the necessary fields (p1 to p4).

Auto LiftSelect this option if you wish the vibrator baseplate to automatically lift at the end of the sweep depicted by the acquisition type. The baseplate will not lift automatically, however, unless and until the Auto Lift button on the DSD is activated too.

High Line SyncThe High Line Sync option allows you to select a synchronization signal for the T0 time. Click this button and select the desired option in the menu that pops up. The three possible options are:

• Free no synchronization

• Up T0 synchronized on the transition from the negative to positive half period of the High Line signal

• Down T0 synchronized on the transition from the positive to negative half period of the High Line signal.

Note High Line synchronization is irrelevant for a pseudo-random signal.

This function is used to remove the noise radiated by nearby power lines, by means of the following technique:

- High Line noise is intendedly picked up and fed to the DPG (see VE432 Installation Manual).

- The sweeps are ALTERNATIVELY triggered on the positive-going and negative-going transitions of high line noise.

- With an even number of sweeps, any high line noise picked up by the receivers is theoretically removed through the stacking process.


VE432The Radio Management setup

8

The Radio Management setup

Figure 8-14

Get DSD StatusThis option button allows you to choose the moment when each DSD should transmit its status to the DPG, and to choose a return signal:

- “During the sweep”: the DSD will transmit its status during the next sweep rather than in the interval between two successive sweeps. This allows you to save time, but prevents you from using a Return Sweep.

- “At end of sweep”: the DSD will transmit its status at the end of sweeps. Choose this option if you wish to use a Return Sweep. (The Return Sweep is transmitted by a DSD to the DPG during sweeps via the radio link).

Return SignalThis button allows you to specify whether to use a Return Sweep signal. If you tick this option, then you have to specify the vibrator on which the Return Sweep signal is to be picked up, choose which signal to pick up as the Return Sweep on this vibrator, and also choose a Return Pilot.

The Return Sweep is transmitted by the DSD to the DPG during sweeps via the radio link. As a result, if you choose to use a Return Sweep, the DSD status cannot be transmitted to the DPG during sweeps (see Get DSD Status option above).

Vib. 2 Vib. 3 Vib. 10



8

The Return Sweep and Return Pilot are relayed to the central unit via the DPG's Analog Pilot connector.

Return Sweep On Vib #Return Sweep refers to a signal sensed on a vibrator's mechanical parts and transmitted on the radio link to the DPG, for real-time monitoring of the vibration source on the central unit. You have to click in the list box to select (highlight) the vibrator to be monitored.

SignalThis option button allows you to choose which signal to monitor as Return Sweep from six possible options:

• Force Ground force signal

• Macc Mass acceleration

• Mvel Mass velocity

• Bacc Base plate acceleration

• Bvel Base plate velocity

• Ref DSD local reference

Return PilotIf you select a Return Sweep, you have to select a Return Pilot, that is one of the Pilot signals generated by the DPG, shifted by the radio delay, so that it can be used as reference signal by the correlation processor. Choose a Return Pilot from the Pilot signals (P1 to P4) specified in the The Acquisition Type setup (page 285).

Note For radio similarity tests:

• the Return Pilot should be fed to Auxiliary channel 2

• the Return Sweep should be fed to Auxiliary channel 3.



8

Generating a Radio Management Setup1. Select the appropriate Get DSD Status option.

2. If you want to define a Return Signal:

- Tick the Return Signal option,

- Click in the list box to select (highlight) the vibrator you want to monitor (choose a vibrator that responded successfully to the Look function),

- From the Signal option button, select the signal to monitor (Force/Mass acceleration/etc.),

- Choose a Return Pilot (P1/P2/P3/P4),

3. To save and enable your changes, click Apply. (To revert to the former settings, click Reset instead).


VE432The QC Limit setup

8

The QC Limit setup

Figure 8-15

This dialog box allows you to set alert thresholds for some of the Quality Control data fed back by the DSDs. Any threshold being exceeded will cause the QC data of the DSD to be displayed in orange in the main window.

Average Phase Error 0 to 45 degrees.

Maximum Phase Error 0 to 45 degrees.

Average Distortion 0 to 50%.

Maximum Distortion 0 to 80%.

Average Ground Force 0 to 100%.



VE432The QC Choice setup

8

The QC Choice setup

Figure 8-16


Data Computation Domain(“Time” or “Frequency”) This option button is used to specify whether the DPG should output the vibrator QC data in the Time domain (phase error, distortion, ground force) or in the Frequency domain (phase error, ground force).

Extended QCIf you select this option, QC data computed every 0.5 second, can be viewed in real time (i. e. with Auto activated), using the Get QC function. The average QC results computed over a complete acquisition are still available.

(If you do not select the Extended QC option, the Extended QC data is still computed but it cannot be viewed during acquisitions).


VE432The T0 Time setup

8

The T0 Time setup

Figure 8-17

The “T0 time” (or T0 sync code) is a virtual time mark signal terminating every T0 message (message radioed between the DPG and DSDs).

The T0 sync code is used for:

- measuring the radio delays,

- allowing the DSDs to start their sweeps at the same time.

See also Radio functions (page 305).


T0 Repeat Times(Allowable range: 2 to 50).

Specifies the number of T0 data frames in the T0 message. It may be helpful to send more than 2 T0 data frames to increase the reliability of the radio link. However, repeating the T0 data frame causes the T0 sync code (terminating the T0 message) to be delayed with respect to the transmit start time of the DPG radio. The delay may be:

up to 50x311 ms = 15.5 s at 1800 bits/s (base band transmitter)

or

up to 50x467 ms = 23.3 s at 1200 bits/s (modem module transmitter).


VE432The T0 Time setup

8

T0 Mode(“Normal T0” or “Early T0”) Allows you to set the transmit start time of the DPG radio between any two consecutive acquisitions.

• In the “Normal T0” mode, the DPG radio is not switched to transmission until the DPG receives the Firing Order.

• In the “Early T0” mode, the DPG radio is switched to transmission right after the DSD status report is received, irrespective of the expected Firing Order for the next acquisition. The time interval between any two acquisitions is therefore shorter by about 1.7 seconds if the Early T0 mode is used.

FO Window(Allowable range: 3 to 60 seconds).

Must be specified if the Early T0 mode is selected. Stands for a time interval, starting right after the DSD status report is received, during which the Firing Order for the next acquisition is expected.

If no Firing Order is received within the FO window, then the system will return to the normal T0 mode for the next acquisition.


VE432Functions

8

Functions In this section:

• Auto/Manual (page 295)

• Look (page 296)

• Vibrator Fleet (page 298)

• Local Acquisition (page 299)

• Set DSD (page 301)

• Get DSD (page 302)

• Radio functions (page 305)

• Set Servo (page 310)

• Statistics (page 313)

Auto/Manual

Figure 8-18

Clicking Manual isolates the DPG from the 428XL and enables its local functions (e.g. local acquisition). As a result:

• data acquisition in vibroseismic operations is suspended until the DPG is reset to Auto.

• the traffic light of the DPG in the 428XL Activity window turns red.

Clicking Auto connects the DPG to the 428XL (and checks the DSD Setup parameters) allowing it to perform data acquisition (if the VE432 window is ready, with consistent parameter settings, and if the Vib Fleet function has been completed). With Auto activated, DPG local


VE432Functions

8

functions are inhibited; the traffic light of the DPG in the 428XL Activity window is green during sweeps, orange otherwise.

LookThe Look DSD function allows you to select the DSDs to be used in the active crew.

You must have used the Setups menu's Crew command to define a crew (a list of DSDs). The crew consisting of all the DSDs that you “select” through the Look DSD function is referred to as the “active” crew. “Selecting” a DSD with the Look DSD function means initializing the radio transmission between the DPG and this DSD and querying to see if its status is correct.

Prerequisites• Unless already done, select the Manual button in the control panel to

isolate the DPG from the recording unit.

• All the DSDs you intend to select must be in the Remote state (use the “Remote” key on the DSD).

• You cannot use the Look button (i. e. the button is dimmed) until the DPG is connected to the workstation and powered up (communication between the two must be established).

Select1. Using the right arrow button, move the vibrators you want to

initialize (those which are to make up the active crew) from the

Figure 8-19


VE432Functions

8

left-hand list (Available DSDs) to the vibrator list for the desired DPG controller module.

2. Click the Select button. As a result, a message is radioed to all the DSDs chosen in the right-hand list box, thus initializing or re-initializing radio communications between the DPG and those DSDs.

3. All the DSDs that replied successfully are displayed with boldface characters in the Look DSD dialog box's vibrator list. In the case of a multimodule configuration, there is one list for each DPG module:

Figure 8-20

- The vibrator indicators should turn orange, unless the vibrator parameters need to be loaded.

- The indicator of any vibrator that requires parameters to be loaded is shown in blue and the message “DSD#.. Wrong setup DSD table” appears. (Use the Set DSD function to load the parameters).

- If the Vib Fleet function has been performed, those DSDs which are seen by Look and associated with a fleet are shown in green.

- Any DSD that requires the Installation or Initialization routine to be performed is shown in red.

- Any DSD for which the Look function failed is colorless.

The vibrator status bar in the main window is updated


VE432Functions

8

4. If any DSD (Vib xx) fails to reply properly, e. g. because it is not installed or because of radio-communications problems, then the message “No answer from DSD xx Do you want to retry?” appears in a warning dialog box.

AppendSame as Select button, but those DSDs which were initialized when the Look DSD function was last executed are not re-initialized, so they remain “selected”. Therefore, the Append button allows you to add one or more DSDs to the list of “selected” DSDs without re-initializing the whole list.

Vibrator FleetA crew may consist of up to 4 groups of DSDs referred to as “fleets” (one fleet for each vibratory source). The Vib. Fleet function is used to specify the DSDs incorporated in each fleet. Beforehand, you have to run the Look and Set DSD functions.

Clicking theVibrator Fleet button opens a dialog box with a list box for each fleet in the crew. (To specify which fleets are to be used in the crew, see The Vibrator Crew setup on page 266).

Figure 8-21

The left-hand list box (Available DSDs) prompts the list of DSDs available to the crew, i. e. those selected by the Look function but not assigned to any fleet yet. Using the right arrow button, move the

Vib Number

Vib. 2 Vib. 3 R

LeaderVib. 10 Vib. 12


VE432Functions

8

vibrators you want to incorporate into a fleet from the left-hand list box to the desired fleet’s list box.

Double-clicking on any DSD in the list enables or disables the use of the Ready button on this DSD (this also determines which vibrator is the leader). Pushing the Ready button on any DSD is of no effect unless the button is enabled in the Fleet window. (An “R” appears after the DSD number of the leader in the list box, meaning that the use of the Ready button on this DSD is enabled).

After selecting (highlighting) the desired DSDs in each fleet's list box, clicking Go will update the status bar displayed under the function buttons in the main window: a flag appears ahead of each vibrators fleet in the status bar, and those vibrators which are ready in each fleet are shown in green.

Local AcquisitionThis function allows you to check the vibrator equipment separately, as if it were not connected to the recording unit. For a local acquisition the DPG may operate alone, or the DPG and DSDs may operate normally but without being controlled by the recording unit. In that case the Blast command (Firing Order) is replaced by a manual start (Go pushbutton).

PrerequisitesUnless already done, click the Manual button in the control panel to isolate the DPG from the recording unit.

The DSDs that you want to use must be “selected” (see Look on page 296), with consistent parameters.

The green colour means the vibrator is ready to be used in

remote control mode

Figure 8-22


VE432Functions

8

How to use the local acquisition function1. Click the Local Acquisition function button. A dialog box

appears showing the DSDs currently selected in the active crew.

Figure 8-23

2. In the list box, choose (by clicking) the vibrators you wish to use for the local acquisition. If you do not select any vibrator, then the DPG will operate alone.

3. In the Basic Type field, enter the type of basic signal you wish to use. (Basic Types are defined through the Setups menu).

4. Click the option button to choose the execution mode:

Single The basic signal is generated once.

Continuous The basic signal repeats endlessly until you click the Stop button (which appears at the bottom of the dialog box if you choose this option).

5. Click the Go button. The local acquisition executes. In Single mode, the local acquisition ends automatically, without any user action. In Continuous mode, you must click the Stop button to interrupt the local acquisition, which will actually stop after the current acquisition is complete.


VE432Functions

8

Set DSDThis function is used to upload sweep-type parameters from the DPG to the DSDs you specify.

The sweep parameters are read from the table containing all the acquisition types (ACQ#) defined in the VE432 window. They are required in the DSDs for generating the corresponding vibratory sources. The Set DSD function allows you to have consistent parameters in all the DSDs to be used for a sweep. Those DSDs which have inconsistent parameters are shown in blue in the main window's status bar.


The DSDs to which you want to upload sweep type parameters must be “selected”. See Look (page 296).

How to use the “Set DSD” function1. Click the Set DSD pushbutton in the control panel. A dialog box

appears with a list box showing the DSDs currently selected in the active crew (as a result of the Look DSD function).

Figure 8-24

2. In the list box, select (by clicking) the vibrators you wish to load parameters to.

3. Click the Go button.

The orange colour means the DPG and DSD

acquisitions are matchingVib. 1 Vib. 2 Vib. 3


VE432Functions

8

Note With a customized basic signal (Custom option in Basic Type setup), errors may appear at this stage as the Set DSD function checks for consistent parameters from the custom file.

Get DSDThis function is used to import and view the vibrator parameters from one or more DSDs you specify.


The DSDs that you want to query must be “selected”. See Look (page 296).

How to use the “Get DSD” function1. Click the Get DSD button. A dialog box appears with a list box

showing the DSDs currently selected in the active crew (as a result of the Look DSD function).

Figure 8-25

2. In the list box, choose (by clicking) the vibrators you wish to get parameters from.

3. Select the type of units you wish to use to display the results: Metric (kg, daN, etc.) Imperial (lb, lbf, etc.).



VE432Functions

8

4. Click the Go button.

After all the data from the DSDs have been collected they are viewed in a table so that comparisons between DSDs can be made easily.

DSD parametersThe following vibrator parameters from each selected DSD are returned in the results pane when you run the Get DSD function:


VE432Functions

8

Figure 8-26

Results from the two sweeps that were used for the identification process.

100 to 32767 kg100 to 32767 kg100 to 32767 kg1000 to 327670 daN1000 to 327670 daNPolarity (depending on the wiring) of the Reaction Mass, Servo Valve, Torque Motor.

Gain of the Mass LVDT and Valve LVDT (Linear Variable Differential Transformer)- Reaction mass LVDT offset- Main Valve LVDT offset- Torque motor current- Active region of LVDT stroke, in percent.

- Static gain of pilot valve. - Pilot valve cut-off frequency- Pilot valve damping coefficient

- Value of leakage between the two chambers of the reaction mass.- Main valve static gain- Gain weighting in the servo control loop.- Servo control type (Filtered or Raw).

- Amplitude level (0 to 100%) for the DSD's DRIVE "H" key.- Amplitude level (0 to 100%) for the DSD's DRIVE "L" key.- If Auto Level = Yes, Minimum high drive level, in percent.- If Auto Level = Yes, Minimum low drive level, in percent.


VE432Functions

8

Radio functionsRadio functions are used to measure (Compute Radio Delay) or manually change (Modify Radio Delay) the radio delay inherent in radio transmissions between the DPG and DSDs, or to remotely change the radio output levels of the DPG and DSDs (Set Radio Parameters).

Figure 8-27

The radio delay is an essential parameter in the correlation process as it is involved in making the pilot signal synchronous with the sweep signal.

A radio delay is usually measured for a given type of radio transceiver. The Compute function should therefore be run whenever you use a new radio type on your DPG and DSDs, but also at regular time intervals to check the performance of your radio sets. Through the Compute function, a series of five measurement sequences is run to determine the radio delay.

The Radio Delay can also be typed on the workstation’s keyboard (using the Modify function) for example because you want to use a value slightly different from the average radio delay determined by the Compute function.

The “Set Radio Parameters” tab is used to set the transmission output level of the radio units of the DPG and DSDs.

Prerequisites• Unless already done, click the Manual button in the control panel to

isolate the DPG from the recording unit.

• Use the Look DSD function to define your active crew.


VE432Functions

8

How to use the “Compute” function1. Click the Compute Radio Delay tab. The DPG queries the

selected DSDs in succession, via the radio link, based on the scheme described below. See More about the radio delay measurement (page 307).

2. After the radio delay is determined, the DPG radio delay assumes the determined value and, via radio transmissions from the DPG, all corrections to the extra delay are zeroed in the DSDs. For more information on this parameter, see More about the radio delay (page 309).

3. After transmission is complete, the computed radio delay appears in the “Dpg Radio Delay” field, meaning that the Compute function is complete.

Transmission faultsIf the DPG fails to receive a reply from any DSD (a T0 sync on its return trip is expected), the warning message “No T0 reception” shows up in the status pane.

In that case, the DPG will resume the transmission of T0 to this DSD. If the retry is successful (a reply is received), the function will proceed normally unless a total of 8 retries have already been done since the Compute function was initiated, in which case the function is aborted, as a more severe failure is suspected, and the “Measurement aborted (radio trans. errors)” warning message shows up.

How to enter a radio delay (“Modify” function)1. Click on the “Modify Radio Delay” tab.

Figure 8-28


VE432Functions

8

2. In the “DPG Radio Delay“field, enter the value of radio delay that you want to use.

3. Click Go to activate this value.

You cannot enter an individual radio delay for each DSD.

Setting radio parametersClick on the “Set Radio Parameters” tab.

Figure 8-29

• The Radio Level is adjustable from 3% (min) to 100% (max).

• Number of Ready Frames:

• Radio Transmission Delay:

Clicking Go uploads the selected value to all DSDs and Slave DPGs selected by the Select or Append function (Look DSD), and all DPGs.

More about the radio delay measurement

Measurement principleRadio delays are measured using the T0 sync code. This signal is the pseudorandom code transmitted in the T0 message.

Measurement sequencesA measurement sequence may be outlined as follows:

• A T0 message is transmitted from the DPG.


VE432Functions

8

• Upon receiving the T0 sync code, a DSD must transmit this time mark back to the DPG.

• The same DSD transmits the t2 time to the DPG.

• The DPG determines a solution (D1) for the radio delay through the following formula:

where

t1 elapsed time between the moment the DPG transmits the T0 and the moment it receives it back from a DSD.

t2 elapsed time between the moment the DSD receives the T0 from the DPG and the moment it transmits it back to the DPG.

• The measurement sequence is repeated until five measurements (D1, D2, ..., D5) are available on the DPG, irrespective of the number of DSDs in the crew. DSDs are queried in ascending order of fleet# and vibrator#.

• If for example the crew consists of six DSDs, the five solutions are obtained from:

Vib 1 (Fleet 1) D1

Vib 2 (Fleet 1) D2

Vib 3 (Fleet 2) D3

Vib 4 (Fleet 2) D4

Vib 5 (Fleet 3) D5

Vib 6 (Fleet 3) not queried

But if there are only two DSDs, the five solutions are obtained from:

Vib 1 (D1)

Vib 2 (D2)

D1 t1 t2–2

----------------=


VE432Functions

8

Vib 1 (D3)

Vib 2 (D4)

Vib 1 (D5).

Radio delay, final resultThe radio delay is then computed by averaging the five solutions. The expression of the final result is then:

(Typical value with standard radios: 500 microseconds approx.)

More about the radio delay

DefinitionThe radio delay may be defined as the time elapsed between the moment a command intended for a DSD is requested on the DPG and the moment it starts running on the DSD, that is the propagation time of a message from the DPG to a DSD via the radio.

System requirementsA record sequence requires that all pilots and sweeps should start at exactly the same time.

If no provision were made for synchronous start times, a Firing Order transmitted from the DPG at time t would result in a premature generation of pilots, or in a delayed generation of sweep start times, due to the delay introduced by the radio sets.

How the system can generate synchronous pilots and sweepsPilots are postponed by a time delay, starting from the T0 sync code, in order to compensate for the radio delays: all pilot start times are postponed by a time equal to the radio delay, computed or user-set, to match the sweep start time (affected by the radio delay) in the DSDs.

RadioDelay D1 D2 D3 D4 D5+ + + +5

----------------------------------------------------------------=


VE432Functions

8

Set Servo

This function allows you to set the parameters used in each vibrator's servo control loop. Clicking Go will set the servo control loop parameters of all the vibrators you select (highlight) in the list box.

Figure 8-30

PrerequisitesUnless already done, click Manual in the control panel to isolate the DPG from the recording unit.

The DSDs that you want to set must be “selected” (see page 296 - Look DSD function).

Servo InputThis option button determines what to use as input to the servo control: either the estimated states from the Kalman filter (“Filtered” option) or raw measurements of baseplate and mass accelerations (“Raw” option).

• Filtered: using this option allows the system to discard non-coherent measurements on any sensor (baseplate acc., mass acc., valve or mass LVDTs). Remember that the QC and the usual way of testing the equipment with external devices always involve the force derived from raw acceleration measurements. Therefore, in the presence of



VE432Functions

8

vibrator imperfections (e.g. mass rocking & baseplate flexure) a raw QC can exhibit larger errors than the real performance of the servo loop.

• Raw: with this option, servo control and QC are homogeneous but the system cannot benefit from the capability of discarding incorrect measurements. This option is of no effect on a random sweep.

Auto LevelThis button allows you to enable or disable the Auto Level function. If you enable the Auto Level function, then you must specify lower limits for both High and Low drive levels.

DSDs using the Auto Level function operate as follows:

• The Drive level is decreased for the next sweep if an overload condition is detected. However the drive level cannot go below the values of Min High Drive and Min Low Drive.

• The Drive level is increased for the next sweep if no overload condition is detected. However the drive level cannot exceed the values of High Drive Level and Low Drive Level.

DSDs not using the Auto Level function will operate only within the limits of “High Drive Level” and “Low Drive Level”.

Low Drive LevelLower amplitude, in percent, of drive level. The scale is adjustable from 0 to 100% in 1% steps.

Requirements: Low Drive Level < High Drive Level.

High Drive LevelUpper amplitude, in percent, of drive level. The scale is adjustable from 0 to 100% in 1% steps.

Min Low DriveThis scale appears only if Auto Level is selected.


VE432Functions

8

Low limit of Low Drive Level, in percent. The scale is adjustable from 0 to 100% in 1% steps.

Requirements: Min Low Drive < Low Drive Level.

Min High DriveThis scale appears only if Auto Level is selected.

Low limit of High Drive Level, in percent. The scale is adjustable from 0 to 100% in 1% steps.

Requirements: Min High Drive < High Drive level.

Lift Up DelayTime interval between the end of a sweep and the moment when a vibrator's pad will lift if Auto Lift is enabled. Adjustable from 0 to 99 seconds.

If no delay is required, set the Lift Up Delay to 0.


VE432Functions

8

StatisticsWhether for statistics on DSDs or on a fleet, the following distinct views are available: average phase, peak phase, average distortion, peak distortion, average ground force, peak ground force, Status Codes.

The system calculates the statistical data from the results collected since it last went to Auto (meaning that your statistics views are lost each time you go to Auto).

Figure 8-31

Unless you choose the Manual range option, the horizontal scale is automatically adjusted so that all samples can be shown. If you choose Manual range, then the associated fields prompt the outermost values


VE432Functions

8

of the horizontal scale, so that you can change them and adjust the scale manually.

You can zoom in by double-clicking on the bar chart, and zoom out by double-clicking again on it.

With the mouse pointer resting anywhere on a bar chart, pressing the mouse right button causes a menu to pop up with three commands.

Show curveUsed to show or hide the Gaussian curve.

Show gridUsed to show or hide the plot grid.

Properties Number of bars

This field is used to specify the number of bins you want to generate in the bar chart.

Bar labels

This option button is used to select the type of annotation to be displayed above each bar:

- Percentage of values contained in the bin, with respect to the whole set of values.

- Number of values contained in the bin.


VE432Normal acquisition

8

Normal acquisitionIn this section:


• Graphic view (page 316)

• Numeric view (page 319)

• DPG/DSD status codes (page 321)

GeneralThe DSDs that you want to use for normal acquisition must be “selected”. See Look (page 296), with consistent parameters (i. e. each DSD to be used should appear with a green indicator in the main window's status bar).

When you are ready for a normal acquisition, click the Auto button, in the main window's control panel. As a result the DPG is waiting for the Firing Order from the 428XL.

The 428XL will not generate the F O until it receives a Ready status from the DPG window. When the Ready signal is received from the vibrator fleet leader, that is when all the desired vibrators are in place with pads down, it may be retained in the DPG window or automatically relayed to the recording system, depending on whether the fleet’s button in the status bar is released or depressed.

When it receives the F O the DPG generates the Time Break to the selected DSDs. Then the programmed sweeps are taken and all DSDs in turn transmit their latest status reports, corresponding to one or more completed sweeps, to the DPG.

The Status and QC data generated by the DPG are relayed to the GUI via the Ethernet link and stored into a daily file automatically generated in the Log window and named “normalAcqResult.hci428_0.ddd” where ddd stands for the julian day when the file was created. (They can be viewed in the Log main window).



8

QC and status results are not only saved but also displayed in the VE432 main window which makes it easy to appreciate the quality of a vibrator in real time or through statistical post-processing. The results can be presented in numeric or graphic form.

The colour of the QC data depends on the alert thresholds you set using the “DSD limits” command in the Setup menu.

The radio link allows the DPG to see if any DSD failed to sweep for any T0. In that case the DPG will report a 98 status (“no T0 received”).

For each status report received the DPG checks to see if the DSD and DPG clock frequencies are the same. If that is not the case it replaces the current status by a Timing Error (status 19).

If the Extended QC option is enabled (see The QC Choice setup on page 292), the QC data can be plotted in real time in the results pane by clicking the Get QC function button. To revert to the normal view, click the Vibrator Fleet function button.

Graphic viewThe VP and Acq fields respectively display the Vibrated Point number and Acquisition number the results relate to.

Six bar charts are shown, for the following QC data available in the status messages from the DSDs: Average Phase, Peak Phase, Average Distortion, Peak Distortion, Average Ground Force, Peak Ground Force.

A red horizontal line in each chart shows the limit specified in the Setup menu (“QC Limit“command).



8

Figure 8-32

For each DSD used, each chart shows:

• A green or orange bar showing the QC value for the latest acquisition completed (identified in the Acq field):

- Green if the QC value is below the limit,

- Orange if it exceeds the limit or an error is reported:

OV for an overload,

W for a warning,

T for a timing error.

Current QC value of the sweep computed

Average values over the latest sweeps



8

F for a file error.

- If the status code from any DSD is incorrect it is displayed in place of the corresponding QC value.

• A blue or red bar showing the average QC value over the latest 50 acquisitions:

- Blue if the average QC value is below the limit,

- Red if it exceeds the limit.

- If the status code from any DSD is incorrect it is displayed in place of the corresponding QC value.

For the interpretation of Status codes, see page 321.



8

Numeric viewA table is displayed, derived from the QC reports of the latest 50 acquisitions. For each DSD, the table shows:

• the Vibrated Point number and the Acquisition number,

• the Average/Peak Phase, or Distortion or Ground Force, or the Status Code, whichever you choose from the QC option button.

Figure 8-33

The colour of each cell in the table should be interpreted as follows:

• If you choose the Status Code view:

- White background, black writing: QC values are within the limits.

- White background, orange writing:



8

- status code 1 or 12 appears, QC values are within the limits but an Overload and/or Warning has been reported.

- or status code 19 appears.

- White background, nothing displayed: no response from the DSD.

- Orange background, black writing:

Status codes 1 or 12, or 19 appears, one of the QC values exceeds the limits, no Overload, and no Warning.

- Orange background, white writing:

Status codes 1 or 12, or 19 appears; one of the QC values exceeds the limits and an Overload and/or Warning is reported.

- Red background, white writing: if any other status appears.

• If you select any of the QC views, the colours should be interpreted in the same way, but only the selected QC is tested for compliance with the limit.

For the interpretation of Status codes, see page 321.

Double-clicking in any cell opens a secondary window showing the detailed QC values contained in the status report from the corresponding DSD for the corresponding acquisition (see Figure 8-33 on page 319).The following codes may be reported for overloads:

F Raw ground Force reaches hold-down weight.

P Computed Pressure reaches maximum hydraulic pressure.

M Mass position exceeds usable stroke.

V Valve spool position exceeds usable stroke.

E Torque motor current, computed, exceeds maximum allowed current.



8

The DSD status reports are logged into the database. They can be viewed in the Log main window and saved to a file.

DPG/DSD status codes1 Normal completion with “Servo Input = Raw”.

2 Sweep aborted by DSD. Hardware malfunction (DVC).

10 User abort.

12 Normal completion with “Servo Input = Filtered”.

13 Discrepancy in DPG and DSD acquisition tables. Use the Set DSD function to correct the inconsistent table.

14 Lift not ready.

19 Normal, Timing error (indicative of discrepancy between DPG and DSD clocks)..

20 HiLine error (Master DPG only).

21 Sweep # undefined.

22 Custom error (Custom sweep does not exist on PCMCIA card) or can not read from PCMCIA card.

25 DPG time-out (Master DPG hardware failure).

26 The Slave recording unit failed to start (on a Slave DPG only).

98 No T0 data received (sweep failed to start, or radio malfunction).

99 No T0 data received or no status report (sweep failed to start or DPG failed to receive consistent DSD status).



8


Chapter

9 Log



• Editing/saving/loading 428XL parameters (page 327)

• SPS files (page 329)

• The Shooting setup window (page 333)

• Operator reports (page 336)


LogThe main window

9

The main windowTo open the Log main window, click on this icon in the launcher bar.

Figure 9-1

The Log window performs two important but somewhat unrelated tasks. One is to provide facilities for handling input and output of text-based (i.e. non-seismic) data, for example observers' logs, processing support files, and vibrator QC results. This is often referred to as “binning in & out”.

The other is to provide a means of setting up the format for printed copies of the observer's report.

For each shot or VP acquired, the 428XL stores around 100 parameters in what is termed the “Raw Observer's Log”. These include the date, time and record number but also a multitude of internal and system-generated figures.

Where available, source position and quality control measurements are also logged on a daily basis. Receiver array quality control measurements form a third category of data, stored in a separate file.

Double-click to expand/collapse

Double-click (or right-click and

select open)

Navigation paneView pane


LogThe main window

9

Some of these parameters are critical, others are of less significance, but any or all can be selected for output in one form or another. The Log window therefore provides several predetermined file formats and also the means of defining customised file-types where necessary. The most common output file format is of course SPS.

SPS files can also be used to pre-program the 428XL via the Log window. The SPS-R, -S and -X files are each loaded in turn, and together with a few additional parameters entered by the observer, provide a rapid means of setting up the system for production.

The toolbar

Figure 9-2

The navigation paneThe navigation (left-hand) pane behaves like a file browser box. To open any folder, double-click on it (or right-click on it and select “Open” from the menu that pops up). The content is viewed in the right-hand pane.

The navigation pane provides an image of the system’s database. It is important to realize what is meant by the term “database” in this context. It is easy to imagine that all of the system data is somehow assembled into a single giant list, but this is not quite the case. Stored under the general banner of “database” are the following:

• All system and survey parameters defined in Setup menus.

Saves content of selected view to

named file

Loads saved file to new view pane

Closes all views

Shooting parameters

Used to type in text to find in selected view

Starts search

Activates parameters contained in selected

view

Opens a blank view


LogThe main window

9

• Pre-acquisition position information including source and receiver coordinates, assuming that these have been supplied.

• All post-acquisition results, for instance Observer's logs, actual source positions and receiver / source attributes and statistics.

Each set of data is stored in a separate file, but it is not necessary for the user to know the file or directory name, since the system automatically keeps track of this itself. Loading a particular data set into the main window and then choosing Apply instructs the system to locate the appropriate file and copy the new data to it. Similarly, the navigation pane gives a straightforward way of extracting a particular set of information, so that you can export it to whatever you want.

View panesFor details on how you can arrange the views and toolbars as you would like them, see the Hands-on guide (page 22). Each view behaves like a simple text editor where the keyboard and usual key combinations for Cut, Copy and Paste shortcuts are allowed. If you want to find any particular parameter or value in a view pane, simply type it into the Search field and click the Search button .


LogEditing/saving/loading 428XL parameters

9

Editing/saving/loading 428XL parametersThe Log window allows you to edit all or part of your system and survey parameters at any moment and save them to a named file so that you can load them back at a later date, for example if you want to reuse the same settings or not much different ones.

You can choose to open the Parameters folder (to view the whole set of setup parameters), or any of its subfolders (to view only the parameters of a particular client window).

Figure 9-3

Opening any folder adds a view pane to the right that allows you to edit its content. For example you may wish to enter the precise coordinates of the recording truck in order to place it at the exact location in the Positioning window (see Figure 9-3).

If you want to find any particular parameter or value, simply type it into the Search field and click the Search button.

To apply your parameter settings to the system, click in the view pane and select Apply from the Setup menu (or use this toolbar button: ).

Search field

Search button


LogEditing/saving/loading 428XL parameters

9

Saving

After you open any folder, you can save its content by clicking in its view pane, then selecting Save from the File menu (or from the toolbar). In the dialog box that shows up, enter a name for the file (in the “File Name” field), choose a directory where to save it (from the “Save In” option button), and click Save.

LoadingTo load back a parameter file previously saved, select Load from the File menu (or from the toolbar). In the file browser box that shows up, choose the desired file and click Open. This adds a view pane in the main window (the file name appears in the tab of that view pane). At this stage, the parameters are only viewed. To load them to the system, click in the view pane and select Apply from the Setup menu (or use this toolbar button: ). You cannot do that unless you turn off the lines in the Line window (by clicking on ).


LogSPS files

9

SPS filesIn this section

• The SPS format (page 329)

• Importing an SPS file (page 330)

• Exporting an SPS file (page 332)

The SPS formatThe SPS format defines four types of files used to input or output some of the setup parameters of a seismic data acquisition system:

• Source file (also called SPS S-file) including source positions,

• Receiver file (also called SPS R-file) including receiver positions,

• Relation file (also called SPS X-file) used to relate the S-file and R-file,

• Text file (also called SPS T-file) including textual information.

For a description of the SPS format, see 428XL User’s Manual Vol. 2.

Note the following restrictions as compared with the standard SPS format: numerals are required in the Line Name, Point Code and Field Tape Number fields.


LogSPS files

9

Importing an SPS file

IMPORTANT

Always import the SPS files in this order: Receiver, Source, Relation.

Select Load from the File menu (or from the toolbar ).

1. In the file browser box, go to the folder containing the file to import and then select that file.

2. Click on Open. This opens an editor view containing the imported file and allowing you to make any changes needed.

3. If several views are open, select the one you want to load (click on its tab).

Figure 9-4

(2) Click to open in editor view

(1) Click to select

(4) Click to apply

(3) Click to select


LogSPS files

9

4. Choose Apply from the Setup menu (or use this toolbar button ). You cannot do that unless you turn off the lines in the Line

window (by clicking on ).

Depending on the type of file in the selected view, clicking Apply will have different effects:

• With a Receiver-type (SPS-R) file, clicking Apply initializes the planned Receiver positions in the Positioning main window.

• With a Source-type (SPS-S) file, clicking Apply initializes the planned Source positions in the Positioning main window.

• With a Relation-type (SPS-X) file, clicking Apply builds an Absolute Spread in the Line main window and sets up the operation table in the Operation main window. The parameters specified with the The Shooting setup window (page 333) also used in generating the operation table.


LogSPS files

9

Exporting an SPS fileIn the navigation pane, open the Results folder and Logs subfolder. Open the desired swath folder and then do the following:

1. Right-click on the log file you want to export. Choose the appropriate SPS output format (S, R or X) from the menu that pops up, depending on which type of SPS file you want to create (Source, Receiver, or Relation). This opens an editor view containing the resulting file and allowing you to make any changes needed.

Figure 9-5

2. If several views are open, select the one you want to save (click on its tab).

3. Select Save from the File menu (or from the toolbar ). In the dialog box that shows up, enter a name for the file (in the “File Name” field), choose a directory where to save it (from the “Save In” option button), and click Save.

(1) Right-click to open

(2) Click to select view

(3) Click to save


LogThe Shooting setup window

9

The Shooting setup window Selecting “Shooting Setup” from the Setup menu opens a dialog box that allows you to enter parameters which cannot be derived from an SPS Relation file (when you generate parameter scripts from an SPS Relation file). These are the type of gain, the Process Type and the shot identification number for the first shot in the operation table.

Figure 9-6

This window must be set up prior to any attempt to load SPS IN files. (Click Apply to save and enable your changes).

The Shooting parameters will be used in generating an absolute spread (for the Line window) and an operation table (for the Operation window) from a “Relation” SPS file viewed in the Log window.

Gain Type Nb You can program gain characteristics that vary as a function of the distance from the shot point, by defining different zones within circles around the shot point. Each zone is allocated a channel type.



9

• Default This field is used to specify the channel type to be used outside the widest circle.

• Radius

• Gain Type The “Radius” and “Gain Type” fields are used jointly, to define circular areas around the shot point and associate a Gain Type (i. e. a preamp gain) to all receiver channels located within the specified distance from the shot point.

Enter the desired distance (1 to 9999 m) in the Radius field and the desired associated Gain Type (1 to 5), and use Add, Change, Delete as required to generate a list of different channel type areas.

Note If the Radius / Gain type table is empty, the default channel type will be used across the entire spread.

Shot Id.Used to identify the first shot point in the Operation main window's operation table. You can use one of the option buttons to choose either the number contained in the “Record Number” field or that in the “Tape Number” field of the SPS Relation file, or type the desired number in the text box.

Process TypeUsed to specify the Process Type (1 to 16) to use in the operation table. Process types are defined using the Operation main window’s Setup menu.

If you do not enter any value in this window, then the system will default to the following settings:

Gain Code Input scale FDU DSU

g1 1600 mv 0 dB 4 m/s²

g2 400 mV 12 dB 1 m/s²



9

• Gain Type: will automatically default to “1”;

• Shot Id.: the Record Number contained in the Relation file will automatically be used as first shot number;

• Process Type: will automatically default to “1”, except for those shot points for which a Point Code is specified in the “Source” SPS file. Because it is desirable to be able to specify the process type to be used for each shot, even though no provision is made for this parameter in the SPS format, Sercel has adopted the following convention: if zero is entered here as the “Process Type”, then the value found in the “Point Code” column in the SPS Source file will be used as the actual process type to use.

For this reason, it is recommended that when SPS files are loaded, the sequence: Receiver, Source and Relation (alphabetical order - R, S, X) be adopted.


LogOperator reports

9

Operator reportsIn this section:

• Observer Logs (page 336)

• APS (page 337)

• APS Verbose (page 338)

• Source COG (page 338)

• Receiver position history data (page 338)

• VE432 QC (page 339)

Observer LogsIn the navigation pane, open the Results folder and Logs subfolder. Open the desired swath folder and then do the following:

1. Right-click on the log file you want to export. Choose Observer Log from the menu that pops up. This opens an editor view containing the resulting file.

2. You can choose which fields to include in the report by clicking on any column heading and selecting “Customize” from the menu that pops up. For details, see Customizing tables (page 27). After customizing the format of a report, clicking on Save will let you save your options to a named file that you can reuse as a template at a later date (by choosing it from the “Select a Preset” option button and clicking Apply). To save you changes, click OK.

3. If several views are open, select the one you want to save (click on its tab).


LogOperator reports

9
Figure 9-7
4. Then you can print it out (e. g. using the File menu). If you want to export it to another program, select Save from the File menu (or from the toolbar ). In the dialog box that shows up, enter a name for the file (in the “File Name” field), choose a directory where to save it (from the “Save In” option button), and click Save.

APS(VE432 users only).

Vibrator QC and co-ordinate information can be exported in the form of SPS-like files to an external computer for the purpose of QC analysis or to the Positioning main window for geographical display.

The APS option extracts the status figures returned for every sweep by each vibrator. Any field with invalid data is left blank. Unless the coordinates supplied by the radiopositioning receiver to the DPG are

(1) Right-click to open

(2) Right-click to customize


LogOperator reports

9

already in a projection format, the vibrator coordinates are converted using the projection selected in the Positioning window. Check to see if the appropriate projection is selected.

(See the format in 428XL User’s Manual Volume 2).

APS Verbose(VE432 users only). As the name suggests, the verbose version gives additional information (See the format in 428XL User’s Manual Volume 2).

Source COGThe following information on the Centre Of Gravity of the source is logged into a daily file identified by its julian day:

• Identification (Line Number, Point Number, Point index from the input SPS Source file) of the planned shot points,

• Position and QC status of the computed COG,

• Deviation between planned source positions and actual source COG positions.

The file can be exported in SPS-like format (see 428XL User’s Manual Vol. 2 for the detailed format).

Receiver position history dataThe following information, collected and saved to a history file during operation, can be viewed and exported:

• Type of field unit identified,

• Date and time when it was last seen,

• Receiver position occupied when it was last seen,

• Geographical position (if supplied) occupied when it was last seen.

(See 428XL User’s Manual Vol. 2 for the detailed format).


LogOperator reports

9

VE432 QC


LogOperator reports

9


Chapter

10 Plotter



• The Banner setup (page 345)

• Selecting the traces to plot (page 351)

• Plot parameters for production shots (page 354)

• Test records (page 361)


PlotterThe main window

10

The main windowThis client window is dedicated to parameters that define what is displayed on monitor records and how it appears.

Figure 10-1

PLOTTER software is dedicated to processing the geophysical data (scaling, filtering, AGC) for plotters. It supports 12'' and 24'' Plotters (selection should be made in the Install window).

It performs the conversion to graphic data (rasterisation) in order to print it out.

Whatever the interpolation, the maximum number of samples of each trace plotted is 14844.

Note Traces are numbered from bottom to top, Aux traces at the top.



10

You can choose to display the complete data (or part of it) for every shot, or display one and the same trace for all shots.

By navigating in the left-hand pane, you can access different setup menus that allow you to adjust AGC and plot parameters differently depending on the type of input data (normal shot, Field tests, Instrument tests).

• The “Normal” folder contains your plot parameters for production shots. It allows you to have special settings for shots with no processing (in the “Raw” folder) and different settings for shots with correlated and/or stacked data (in the “Vibro Stack” folder).

• The “Field Test” folder, as the name suggests, contains your plot parameters for sensor tests (Noise, Tilt, Distortion, etc.).

• Likewise, the “Instrument Test” folder contains your plot parameters for instrument tests (Noise, Distortion, Gain&Phase, CMRR, Crosstalk, etc.).

Once the different parameters are programmed and activated (by clicking on Apply), the system automatically uses the sets of parameters matching the input data.

File menuUsing the Load / Save commands available from the File menu, all of the current parameters that have been set up for the entire window can be saved to or loaded from a named file. This feature can be useful for storing configurations that have to be used periodically.

Warning: After installing a new software release, do not load any parameters from files saved with earlier releases.

Plot AgainThis button plots the last shot.

Plot NextThis button plots the next shot.



10

Abort PlotThis button stops the paper feed and cancels the current plot.


PlotterThe Banner setup

10

The Banner setupTo open this window, choose Banner from the Setup menu. It allows you to choose which parameters to import from the seismic record file and build the banner as you would like it to appear on your plots.

Figure 10-2

In the navigation pane on the left side are a number of folders containing all the parameters that you can import into a banner. Choosing any of them, by double-clicking on it (or dragging and dropping it into the right-hand pane) causes the associated building block to appear in the right-hand pane.

The right-hand pane is a text editor in which you can:

- Create a new line by pressing the Return key;

- Type any additional text you like;

- Select a text span by clicking before the first character to select, pressing and holding down the SHIFT key , and then clicking behind the last character to select (alternatively, you can press and hold down the mouse left button and drag the mouse over the text span to select).

- Move or delete text with the usual Cut, Copy & Paste key combinations (CTRL+X, CTRL+C, CTRL+V).

The list box shows the list of existing banner formats. To define a new banner format, enter its number in the Nb field and then click Add. To

Building blocks



10

make any changes in the list box, click on the desired row. To save your changes, click Change (or Add, or Delete).

Double-clicking on a banner format in the list box has it appear in the text editor so that you can make any changes required. To save your changes, click Change (or Add, or Delete).

To save the current list of banner formats, click Apply. (To revert to the former list, click Reset instead).

Global parameters

Record parameters

Parameter Description

Sample Rate Sampling interval (ms)

Type Of Filter

Swath Id

Swath Name

Exploitation mode

Date

Julian day Record day (1 to 366)

Year Record date (year)

Acq. Time

Acq. hour

Acq. minutes

Acq. seconds


File nb. File Number

Record Type

Record Length

Trace headers Errors



10

Process parameters

Line parameters


Type of process

Auto cor. peak time Autocorrelation peak time

Max of max aux.

Max of max seismic

Max time values report


SFL Lowest Line Number in the Spread; specifies the origin of the spread (along with SFN).

SFN Lowest Receiver Position Number in the Spread; specifies the origin of the spread (along with SFL).

Spread Nb

Type Of Spread

Live seis. traces Active seismic traces

Nb. of Live traces Number of active traces

Dead seis. traces Dead seismic traces

Nb. of dead traces Number of dead traces

Total nb. of traces Total number of traces

Nb. of seismic traces Number of seismic traces

Nb. of aux. traces Number of auxiliary traces

Total nb. of samples Total number of seismic samples contained in a block

Blaster Id Blaster Identification Number

Blaster status



10

Shot parameters


Shot Nb Shot Number

Source Point Line

Source Point Nb Source Point Number

Source Point Index

Acq. length Acquistion length

Sweep length

Pilot length

Refraction delay

Current Stacking Fold

Stacking Fold

Source Easting

Source Northing

Source Elevation

Type of source

Uphole time

Tb window

User header



10

Noise parameters


Noise EIim. Type Noise EIimination Type (

Threshold var Threshold option (Hold or Variable)

History editing type

History range

History taper length

History threshold init value

History zeroing length

Nb. of windows Number of windows

Low traces percent

Low traces value

Noisy traces percent

Noisy traces value

Low noisy verbose report



10

Plot parameters


Plot type

Plot Control Type

High cut

High cut filter

Low cut

Low cut filter

Notch filter

Notch

Aux. gain

Seismic gain

AGC window length

WZ velocity

Inline spacing

Crossline spacing

Release time

Time exponent


PlotterSelecting the traces to plot

10

Selecting the traces to plotFor each type of record (production shots or tests), you can choose to plot all traces or only groups of traces you specify, or one and the same trace. To do that, you simply have to create a table containing the description of each group of traces you would like to plot, for each type of record:

1. Click on the desired type of record, e. g. the “Raw” subfolder (see Figure 10-3) in the navigation pane to the left;

2. Enter the desired number of groups into the “Number of groups” field;

3. Click in the “Group” field. As a result, the system automatically creates the appropriate number of rows in the table so that you can define each eligible group as you like with the parameters described below.

4. Click on Apply.

Figure 10-3 Selecting the traces to plot

Number of groupsThis field is used to tell the system how many groups you want to describe, so that it can create the necessary number of rows in the table.

Use these fields to determine the recurrence rate of the selected group or groups.

1. Choose type of record

2. Specify how many groups you want to

describe

3. Click to create the necessary rows in table



10

GroupAs you click in this field, the system automatically creates a row for each group of traces to describe, depending on what you specify in the “Number of groups” field.

A button is associated with each group (row), on the left of it, in the table. You have to tick that button if you want the group to be plotted when eligible. Its recurrence rate on the printout depends on what you specify in the fields at the foot of the table, determining “how many” groups will be plotted and “how often” (every N records).

Figure 10-4

AuxTick this button if you want to plot auxiliary traces.

Sensor codeThis field lets you to choose either all the traces specified regardless of the type of sensor, or only traces with the type of sensor you specify.

Channel/LineChoosing Channel lets you determine the eligible group by specifying the first trace to plot (“Start at” field), the number of traces to plot (“Total” field) and the step (“Incr” field) to use in counting the traces. The same group of traces from all lines will be eligible for plotting.

Choosing Line lets you determine the eligible group by specifying the first line to plot (“Start at” field), the number of lines to plot (“Total” field) and the step (“Incr” field) to use in counting the lines. All the matching traces on the specified lines will be eligible for plotting.

How oftenHow many

groups



10

Start atUsed to specify sequential number of either the first trace or the first line (depending on whether the “Channel” or “Line” option is selected) eligible in the group.

TotalUsed to specify either the number of traces from each line or the number of lines (depending on whether the “Channel” or “Line” option is selected) eligible in the group.

A button is associated with the “Total” field. If you tick that button, then system will automatically determine the total number of traces eligible in the group, depending on what you specify in the other fields. If you untick the button, then you have to specify how many traces or lines you want the group to include.

IncrUsed to specify the sequential number increment step for counting in either the traces or the lines (depending on whether the “Channel” or “Line” option is selected) eligible in the group.


PlotterPlot parameters for production shots

10

Plot parameters for production shotsIn this section:

• Processing setup (page 354)

• Rendering setup (page 358)

• Format setup (page 358)

Processing setupSome of the parameters appearing in the Processing pane are specific to the kind of data to be plotted. Below is a description of all the parameters prompted after you click on the Normal folder in the navigation pane.

Figure 10-5

Choose the desired processing from the “Control” option button, then set the associated parameters.

AGCFor “Normal” shots only. With the AGC processing option, the gain of each trace is automatically adjusted, depending on the level of the signal.

If you choose this option, the system computes the average sample value over a time window you have to specify in the associated “Window Length” field.



10

The average value is used to determine a gain that is applied to the sample at the centre of the window. The system repeatedly updates the average value as the time window shifts from the time when AGC starts being applied to the end of the plot.

Geographic AGCFor “Normal” shots only. The Geographic AGC processing option lets the system compute source-to-receivers distances from the geographic coordinates available (you do not have to supply the “Inline spacing” and “CrossLine spacing”).

Note: You have to click on Apply after entering SPS data.

Time exponent(0.00 to 9.00). For “Normal” shots only. If you choose this option, the same gain is applied to all traces. The gain increases as an exponential function of the time over the whole trace. You simply have to specify the value of the exponent.

NormalizationFor “Normal” shots only. If you choose this option, then the system will look for the maximum sample value on each trace to determine the appropriate gain to be applied to the whole trace.

Window Length(100 to 5000 ms). For “Normal” shots only. Time interval over which the system computes the average value of samples to determine the AGC gain, if the AGC or Geographic AGC option is used.

Wz Velocity(Allowable range: 1 to 99999 m/s). For “Normal” shots only. If you choose AGC or Geographic AGC as a processing to plot the traces, a “Wz Velocity“field is available that allows you to specify the propagation velocity of the shot wave. This will enable the system to



10

calculate the time when the AGC should be applied to the traces on the plotter, deducing it from the source-to-receivers distances.

Note By default the source-to-receiver distance is assumed determined in metres, therefore the velocity in metres/second. If the distance is determined in any other unit, then the velocity you enter should be expressed in the corresponding unit instead of m/s (the unit must be consistent with SPS data).

Inline spacing(1.0 to 999.0 m). For “Normal” shots only. Distance between receiver points (i. e. traces) in each line. Used to determine the time when AGC should be applied, unless you choose the Geographic AGC option.

CrossLine spacing(1.0 to 999.0 m). For “Normal” shots only. Distance between lines. Used to determine the time when AGC should be applied, unless you choose the Geographic AGC option.

ScalingScaling is used to specify an amplitude gain (dB) for the traces plotted, to magnify or shrink the traces. Changing the Scaling setting for any shot will make it more difficult to compare the plot with another shot.

NOTE: Adjust both Scaling and Clipping as required for better legibility of the plot.

• Seismic (-144 to 144 dB). Sets the amplitude of seismic traces on the plot.

• Auxiliary (-144 to 144 dB). Sets the amplitude of auxiliary traces on the plot.



10

FiltersFor “Normal” shots only. These three buttons allow you to specify a Low Cut frequency, a High Cut frequency and a Notch filter frequency for the traces to plot.

Note The three parameters (Low Cut, High Cut, Notch) are not applied to Auxiliary traces.

• Low Cut If you wish to set a low-cut filter for the plot, choose Low Cut and type the desired low-cut frequency (5 to 500 Hz) in the associated field. If you wish to remove the filter, unselect Low Cut.

• High Cut If you wish to set a high-cut filter for the plot, choose High Cut and type the desired high-cut frequency (30 to 500 Hz) in the associated field. If you wish to remove the filter, unselect High Cut.

• Notch If you wish to set a notch filter for the plot, choose Notch and type the desired notch frequency (30.00 to 500.00 Hz) in the associated field. If you wish to remove the filter, unselect Notch.

Note The Low Cut and High Cut buttons allow you to set up different types of filters:

Figure 10-6

F F F High cut Low cut High cut

Band pass

Low cut



10

Rendering setup

Figure 10-7

Page setupAllows you to specify which type of banner to use. This determines the content of the banner to appear ahead of plots. See The Banner setup (page 345).

OrientationThis option button allows you to choose the orientation of plots (Portrait/Landscape).

Format setup

Figure 10-8



10

Time Sequential The traces are plotted along the paper.

Trace Sequential The traces are plotted across the paper width.

Global rendering for Seismic and AuxThis option lets you customize the global aspect of the plotter output by means of the parameters below.

ModeYou can choose between the following options:

Figure 10-9

Traces/inch(Auto or 1 to 99) Number of traces to plot per inch. Choosing Auto will adjust the trace spacing as a function of the number of traces.

Note: Disproportionate labels may result if you choose “Auto” and “Time Sequential” with too few traces to plot.

Clipping(1 to 10 traces) This button is used to specify the number of traces that any trace is allowed to overlap. Any trace exceeding the specified overlapping limit is clipped to that limit.

NOTE: Adjust both Scaling and Clipping as required for better legibility of the plot.

+VA

-VA

Wiggle +VA

Wiggle -VA

Wiggle



10

Time• Start: (0 to 64000 ms) Time of the first sample to plot.

• Length: (Auto or 1 to 64000 ms) If you choose Auto, the system will automatically set the length of the plot to the maximum or to the best, depending on the record parameters. Otherwise, specify the desired length for the plot.

• Interpolation: (Auto or 16, 8, 4, 2 1 to 1, or 1 to 2, 4, 8, 16). Number of dots interpolated by the system for each sample.

If you choose Auto, then the system will automatically set the interpolation to the best, depending on the record parameters.

Examples: 1 to 4 means that 4 dots are plotted for each sample (this expands the plot); 4 to 1 means that each dot stands for 4 samples (this shrinks the plot).


PlotterTest records

10

Test recordsIf you need specific plot parameters for any type of test, choose the desired folder in the navigation pane and then set the parameters as you like. For test records, you have a single processing parameter to set (Scaling). For other parameters, see Rendering setup (page 358) and Format setup (page 358).

Sensor tests

Figure 10-10

Instrument tests

Figure 10-11


PlotterTest records

10


Index

Index

IM = Installation Manual

U1 = User’s Manual Vol. 1



TM = Technical Manual

Numerics3592 cartridge dirve IM: 84

AAbort

· button, Operation U1: 136· Plot U1: 344

Absolute· spread U1: 96· Spread, tests U1: 109

Acceleration· baseplate, monitoring U1: 289· mass, monitoring U1: 289

Acquisition· Error description (SEGD) U2: 22· graphic view, normal U1: 316· index, process type U1: 141· Length (SEGD) U2: 19· local U1: 299· normal U1: 315· Number (SEGD) U2: 22· numeric view, normal U1: 319· type, Process type U1: 142

· type, VE432 U1: 285Acquisition type tables (SEGD) U2: 21Action (see Shortcuts)Activity

· window U1: 58Add

· to query U1: 251Additional

· effects U1: 246Additional blocks (SEGD general

header) U2: 13Address

· FUJI 3x90, changing IM: 74· FUJI 3x90, displaying IM: 75· LCI card U1: 40· LTO, changing IM: 80· MAC U1: 43

Administration· server U1: 29

Advance II U2: 84Advanced

· connection parameters U1: 18· mode, LT428 IM: 137, IM: 148,

IM: 150· process type U1: 140

Again· Plot U1: 343

AGC· plotter U1: 354

Air gun (SPS) U2: 50Air pressure psi (SPS) U2: 64Alarm

· Positioning U1: 241Alert

· system U1: 241Alias filter

· Frequency at - 3dB point (SEGD) U2: 18

· Slope (SEGD) U2: 18Angle from skew (SPS) U2: 46, U2: 58Append

· vib (Look) U1: 298Apply

· All, Survey setup U1: 79· Sensor, Survey setup U1: 79

IM = Installation Manual — TM = Technical Manual — U# = User’s Manual Vol. # 363April 20, 2006

Index

Archiving· configuring U1: 45

Array· Forming (SEGD) U2: 18

Arrays, sub, number of U2: 64Authorization

· granting U1: 29Auto

· Corr Peak Time U1: 143· Level, vib drive U1: 311· Lift, VE432 U1: 287· Look U1: 100· noise editing U1: 173

Auto/Manual· noise editing threshold U1: 173· VE432 U1: 295

Autocorrelation peak time (SEGD) U2: 22

Automation· Continuous, shooting U1: 159· Discontinuous, shooting U1: 160· Look U1: 160· Manual, shooting U1: 160· shooting U1: 159

Aux· Channel contents (SPS) U2: 47, U2: 60· Line U1: 90· Process Descriptor U1: 144· Traces, number of U2: 19

Auxiliary· channels U1: 90· channels, Comments U1: 92· channels, Gain U1: 91· channels, Instrument tests U1: 110· trace scaling U1: 356

Auxiliary channels· Deployment IM: 123

BBackup

· setup U1: 57Backup, GoBook Q200 IM: 110Base scan interval (SEGD) U2: 14Baseplate

· acceleration, monitoring U1: 289· velocity, monitoring U1: 289

Basic· pilot signal (Acquisition type) U1: 286· sweep signal (Acquisition type)

U1: 286Basic Type

· LOG, dB/Hz U1: 272· LOG, dB/octave U1: 275· Setup U1: 269· Taper U1: 269· Tn U1: 276

Batteries (Show/hide) U1: 70Battery

· GoBook Q200 IM: 106· Limit, LT428 IM: 139· voltage limit U1: 70

Beginner U1: 22Blade 2000

· Shock-mount parts IM: 29Blade 2500

· Shock-mount parts IM: 28Blaster

· Advance II U2: 84· connector, LCI428 IM: 218, IM: 219· controllers U1: 176· id (SEGD) U2: 20· MACHA U2: 91· SGDS U2: 92· Shallow Sequencer U2: 89· Shot Pro U2: 85· signals IM: 220· status (SEGD) U2: 20· type U1: 42

Blasters· interfacing U2: 81

Blocking· trace U1: 256

Blocks in General Trailer U2: 15BoomBox U1: 42Box

· type, detour U1: 92Break

· Point U1: 154Browser

364 IM = Installation Manual — TM = Technical Manual — U# = User’s Manual Vol. #April 20, 2006

Index

· settings U1: 17Buffer U1: 40Build

· feature query U1: 250Bypass

· tape U1: 259Bytes per scan (SEGD) U2: 13

CCable

· length, Line IM: 122· Line cable length IM: 122· path U1: 75· replacing, LAUL TM: 23

Calibration· FDU U3: 83

Camp· distance to, alarm U1: 244

Capacitance· error (SEGD) U2: 30· high limit (SEGD) U2: 30· low limit (SEGD) U2: 30· value (SEGD) U2: 30

Capacity· Processing U3: 199

Cartridge drive· Shock-mount parts IM: 72

Centre· button (mouse) U1: 72

Changing· LCI U1: 38

Channel· data error overscaling (SEGD) U2: 34· edited status (SEGD) U2: 34· fibre U1: 40· filter (SEGD) U2: 33· filter response U3: 29· gain control method (SEGD) U2: 17· gain scale (SEGD) U2: 33· increment (SPS) U2: 52, U2: 69· number (SEGD) U2: 31· process (SEGD) U2: 34· sample to mV conversion factor (SEGD)

U2: 34

· Set End Time (SEGD) U2: 17· Set Number (SEGD) U2: 26· set number (SEGD) U2: 17· Set Starting Time (SEGD) U2: 17· set, number of channels in U2: 17· sets per record U1: 56, U2: 14· type (SEGD) U2: 32· type id (SEGD) U2: 34· Type Identification (SEGD) U2: 17· type, Log shooting setup U1: 334

Channels, number of (SPS) U2: 47, U2: 59

Charge· Depth U2: 63· Length U2: 63

Check· Line U1: 116

Checkerboard· view U1: 75

Circular bearing of H256 (SPS) U2: 46, U2: 57

Cleaning· boxes IM: 115· plugs IM: 114, TM: 63

Click· right, Line window U1: 74

Client· installing IM: 55· main window U1: 22· SPS U2: 45, U2: 55

Clipping· method (noise elimination) U1: 193· noise editing type U1: 171· plotter U1: 359

Clock· internal U1: 54· time w.r.t. GMT (SPS) U2: 45, U2: 55

Cluster U1: 166CMRR

· geophone string U3: 174· Instrument test U1: 112· test record result recovery U3: 81· test, FDU U3: 137· test, Sensor U3: 156

COG


Index

· radius threshold U1: 213· source position (estimated) U1: 234

Comments· Auxiliary channels U1: 92· LT428 results IM: 157· observer, setup U1: 175· SEGD U2: 24· setup, Operation window U1: 156

Common· Mode Rejection U1: 112· mode, test network U3: 106

Common mode· rejection ratio, geophones U3: 174

Communications· protocol, source controllers U2: 81

Compound· basic sweep signal U1: 281

Connecting· LT428 IM: 131

Connection· opening a session U1: 17

Connector (see Replacing)Connectors

· Blaster1 IM: 218· Blaster2 IM: 219· FDU Input IM: 222· LAUL

XDEV IM: 223· LAUL428 IM: 223· LAUX

LINE IM: 224Power IM: 224TRANSVERSE IM: 224XDEV IM: 225

Continuity· test limit U1: 84

Continuous· shooting U1: 159

Control· type (SPS) U2: 49, U2: 63· unit serial number (SEGD) U2: 33· unit type (SEGD) U2: 33

Controller· source, time management U1: 54

Conversion

· sample to mV U2: 34Converting

· samples to mV U3: 169Coord. status final/prov (SPS) U2: 50,

U2: 64Coordinate location (SPS) U2: 45,

U2: 55Copy

· tape, file U2: 12CopyMedia U2: 12Copyrights U1: 49Correction

· factor U3: 84Correlation

· After Stack, process type U1: 149· After stack, theory of U1: 195· Before Stack, process type U1: 148· data distribution U1: 201· Frequency domain U3: 166· more about U1: 198· Pilot Aux channel U1: 143· Time domain U3: 166

Correlator, noise supp (SPS) U2: 49, U2: 63

CRC errors U3: 181Create

· selection U1: 251Crew

· name, Comment (SPS) U2: 47, U2: 59· number U1: 266· setup U1: 52· vibrators U1: 266

Crossline· spacing, AGC U1: 356

Crosstalk· Instrument test U1: 111· test record result recovery U3: 82

Custom· basic sweep signal U1: 279· sweep file (how to load) U1: 280

Customer· support U1: 49

Cut off· error (SEGD) U2: 30· high limits (SEGD) U2: 30


Index

· low limit (SEGD) U2: 30· value (SEGD) U2: 30

Cygwin IM: 58

DDAC

· Common-Mode resistance U3: 106· fine current correction U3: 97· rough current correction U3: 91

Damp coeff, natural freq. (SPS) U2: 48Damping coeff, natural freq (SPS)

U2: 61Data

· computation domain, vib QC U1: 292· record sorting order (SPS) U2: 42· Tape Bypass U1: 259

Data rate· Line U3: 199· Transverse U3: 199

Date· of survey (SPS) U2: 45, U2: 54· SEGD U2: 22

Datum U1: 252· type, setup U1: 209

Datum Type setup· Datum U1: 252· Ellipsoid U1: 252· Geoid U1: 252

Day· of year (SPS) U2: 51, U2: 67

Dead seis traces, number of U2: 19Deboost

· basic sweep signal U1: 282Default

· Channel type, Log U1: 334Delay

· at end of Acq. U1: 168· at end of VP U1: 168· basic sweep signal U1: 282· lift up U1: 312· no-move alarm U1: 244· radio, measuring U1: 307· radio, VE432 U1: 305· refraction, process type U1: 141

· setup, Operation window U1: 168· speed alarm U1: 245

Depth· charge U2: 63· towing U2: 64

Descale Multiplier (SEGD) U2: 17Description

· absolute spread U1: 96· Auxiliary channels U1: 90· Channels (Aux), Instrument tests

U1: 110· Channels (tests) U1: 109· Generic Line U1: 98· Generic spread U1: 99· of grid units (SPS) U2: 45, U2: 56· of survey area (SPS) U2: 45, U2: 54· Receiver section U1: 81· Skipped lines U1: 99· Survey U1: 80

Desensitization IM: 177Detour U1: 92

· skipped receiver points U1: 103Disassembling

· FDU TM: 17· LAUL TM: 24· LAUR TM: 36· LAUX TM: 30· LRU TM: 43· TFOI TM: 99· TREP TM: 50

Discharge· ESD protection TM: 12

Discontinuous· shooting U1: 160

Disk· buffer U1: 40· record, setup U1: 57

Display· mode, LT428 IM: 155· Traces per inch U1: 359

Distance· no-move alarm U1: 244

Distortion· Instrument test U1: 111· Sensor test U1: 114, U3: 161


Index

· test record result recovery U3: 74· test, FDU U3: 134

Diversity· stack U1: 170· stack (theory of) U1: 195

DPG· number of U1: 42· Slave U1: 267

Drag and drop· base camp U1: 228· recording unit U1: 228· source (Positioning) U1: 229

Drive· level

high U1: 311low U1: 311

· tape, install U1: 45· transfer to U3: 199

DSD· Get U1: 302· network U1: 267· Network, Navigation U1: 178· reference signal U1: 289· setting U1: 301· status, get U1: 288

Dump· Output button U1: 142

Dump stacking fold (SEGD) U2: 22Duplicating, tape, file U2: 12Duplication, sample U3: 181

Ee428 software

· licence U1: 40Earth

· ground resistor U3: 112Editing

· Noise U1: 170· number of windows (noise) U1: 171· Spike U1: 192· system parameters (Log) U1: 327· type (noise) U1: 171· Zeroing Length (noise) U1: 172· Zeroing Taper Length (noise) U1: 171

Effect· speed alert U1: 246

Electrostatic· discharge TM: 12

Elevation· reference U1: 212

Ellipsoid U1: 252Ellipsoidal

· model U1: 212Emergency

· alarm U1: 241Enabled

· export U1: 251End

· colour map scale U1: 248End-of-line plug IM: 120EOF U1: 260Error

· leakage U1: 101Errors

· CRC U3: 181ESD TM: 12Estimated

· source COG U1: 234Expanded file number (SEGD) U2: 15,

U2: 16Explosive

· source type setup U1: 163Explosive (SPS) U2: 50Exponent, subscans U2: 17Exponential

· basic sweep signal U1: 276· time, plotter U1: 355

Export· enabled U1: 251

Exporting· LT428 results IM: 158

Exports· configuring U1: 45

Extended· channel set number (SEGD) U2: 18,

U2: 26· Channel Sets/Scan Types (SEGD)

U2: 15


Index

· file number (SEGD) U2: 26· header (SEGD) U2: 19· header blocks (SEGD) U2: 15· header flag (SEGD) U2: 18· header length (SEGD) U2: 14· QC, vib U1: 292· receiver line number (SEGD) U2: 27· receiver point number (SEGD) U2: 27· Record Length (SEGD) U2: 15

External· header (SEGD) U2: 24· header blocks (SEGD) U2: 15· header length (SEGD) U2: 14

FFactor to metre (SPS) U2: 45, U2: 57Farthest

· Rcv Nb, LT428 IM: 146FDU

· Calibration U3: 83· connector, replacing TM: 53· disassembly instructions TM: 17· INPUT connector IM: 222· Input polarity IM: 222· Max number between LAUs IM: 122· Number in link, LT428 IM: 164· Power supply IM: 121· reassembly instructions TM: 18· unit type (SEGD) U2: 32

FDU assembly· Location (SEGD) U2: 31· Serial number (SEGD) U2: 31· Type (SEGD) U2: 31

Feature· property names U1: 248

Fibre· channel U1: 40

Fibre Optics· allowable loss TM: 115· connector, replacing TM: 107· repair kits TM: 98· repairs TM: 97· splices, number of TM: 115

Field· computer system(s) (SPS) U2: 45,

U2: 55· record increment (SPS) U2: 52, U2: 69· record number (SPS) U2: 52, U2: 69· tape number (SPS) U2: 52, U2: 69· test limits, LT428 IM: 140· test, automation U1: 160· test, LT428 IM: 150· update mode U1: 63, U1: 113,

U1: 114Field Units (see Instruments)File

· count (SEGD) U2: 22· duplicating U2: 12· Header block (SEGD) U2: 13· Load/Save U1: 343· number (SEGD) U2: 13, U2: 26

Files· per tape U1: 256· per tape (SEGD) U2: 22

Filter· alias Hz, dB pnt, slope (SPS) U2: 47,

U2: 59· low Hz, dB pnt, slope (SPS) U2: 47,

U2: 60· LT428 IM: 137· notch Hz, -3 dB points (SPS) U2: 47· notch Hz, -3dB points (SPS) U2: 60· playback U3: 17· response, channel U3: 29· servo control U1: 310· type U1: 53· type (SEGD) U2: 23

Filters· plotter U1: 357

Firing· Order (FO), process type U1: 140

Firmware· updating U1: 126

First· Notch Frequency (SEGD) U2: 18· Timing Word (SEGD) U2: 26· waypoint U1: 217

Fleet· Ready U1: 166· vibrator, crew U1: 267


Index

Floppy disk· specifications (SPS) U2: 42, U2: 43

FM4 plug assembly· ST+ cable TM: 79· WPSR cable TM: 84

FO Window U1: 294Force

· ground, monitoring U1: 289Form

· Line, LT428 IM: 145· Transverse, LT428 IM: 153

Format· code (SEGD) U2: 13· SEGD U2: 11· Source controllers U2: 81· SPS U2: 37· version num. (SPS) U2: 45, U2: 54

Fourier· Transform U3: 166

Frequency· domain U3: 166· LRU IM: 174· Nyquist U1: 53

From channel (SPS) U2: 52, U2: 69From receiver (SPS) U2: 52, U2: 70FTP

· server U1: 45· server, installing on PC IM: 98

FUJI 3x90· address, changing IM: 74· address, displaying IM: 75

Functions· Test U1: 107· VE432 U1: 295

GGain

· Auxiliary channels U1: 91· code U1: 96· code, absolute spread U1: 96· error, Instrument test U1: 112· geophone string U3: 173· Instrument tests U1: 110· LT428 IM: 137

· Preamplifier, 0 dB U3: 87· Preamplifier, 12 dB U3: 116· Seismonitor U1: 71· shooting setup, Log U1: 333· test record result recovery U3: 75· test, FDU U3: 129

Gap U1: 81· between receiver sections U1: 88

General· Header block 1 (SEGD) U2: 13· Header block 2 (SEGD) U2: 15· Header block 3 (SEGD) U2: 16· Header Block Number (SEGD) U2: 15,

U2: 16· LT428 parameters IM: 133, IM: 137· Trailer blocks, number of U2: 15

Generate· report U1: 251

Generic· spread U1: 97· spread, description U1: 99

Geodetic datum· parameters (SPS) U2: 45, U2: 56· spheroid (SPS) U2: 45, U2: 56

Geographic· AGC U1: 355

Geographic (see Topographic)Geoid U1: 252Geoidal

· model U1: 212Geophone

· arrangement U3: 175· number per trace U3: 172· parallel U3: 173· series U3: 173· strings U3: 172

Geophysical contractor (SPS) U2: 45, U2: 55

Geozone· alarm U1: 242

Get· DSD U1: 302· DSD status U1: 288

Getting started U1: 13Global


Index

· rendering, plotter U1: 359Go

· starting a shot U1: 135· Topographic view U1: 67, U1: 68

GoBook· connecting IM: 131· Getting started IM: 129· Q200 IM: 127

GoBook Q200· Backup IM: 110· Battery IM: 106· Installing IM: 107· quick guide IM: 104· Reinstalling IM: 111

GPS· time management U1: 54

Grabbing· VP U1: 214

Graphic· view, normal acquisition U1: 316· view, Positioning window U1: 218

Graphic view (see Topographic)Grid

· coord. at origin (SPS) U2: 46, U2: 57· origin (SPS) U2: 46, U2: 57

Ground· earth resistor U3: 112· force, monitoring U1: 289· wing nut, replacing TM: 53

Group· geophone string U3: 177

Guest· privileges U1: 30

HHardware

· installing IM: 25Header

· external, size U1: 56Header record

· description (SPS) U2: 54· specification (SPS) U2: 44

Help· language U1: 18

· send, emergeny alarm U1: 242Hide

· layer (Positioning) U1: 222High

· box, detour U1: 93· channel, detour U1: 93· drive level U1: 311· Line, sync U1: 287· SN, detour U1: 93

High-cut· filter, plotter U1: 357· playback filter U3: 18

Historic· editing type (SEGD) U2: 21· range (SEGD) U2: 21· taper length (SEGD) U2: 21· threshold Init value (SEGD) U2: 21· zeroing length (SEGD) U2: 21

Historical· Noise Editing U1: 170

History· Line window U1: 78

Hold/Var U1: 173Hot

· Line U1: 49Hour of day (SEGD) U2: 13

IID

· vibrator U1: 267Identity

· card U1: 50Impedance

· geophone string U3: 173Impulse

· Sensor test U3: 159Impulsive

· process type U1: 146· Stack process type U1: 147

Inactive· units (detour) U1: 92

Increment· LT428 Rcv num IM: 136· Marker U1: 90


Index

· Shot U1: 163· VP to do U1: 165

Indicator· replacing TM: 59

Init· Thresh U1: 173

Inline· spacing, AGC U1: 356

Input· resistance U3: 91· servo control loop U1: 310

Install· window U1: 39

Installing· Client software IM: 55, IM: 56· Ethernet plotter IM: 68· FDPA428 software IM: 107· FTP server on PC IM: 98· Handheld PC software IM: 103· hardware IM: 25· LT428 software IM: 107· patch (client) IM: 63· patch (server) IM: 52· server software IM: 44· Solaris IM: 36· Vehicle tracking box IM: 102

Instrument· Code (I) tables (SPS) U2: 47· Code (SPS) U2: 52, U2: 69· Crosstalk U1: 111· Distortion U1: 111· Gain error U1: 112· Noise U1: 111· Phase error U1: 112· test limits, LT428 IM: 141· test record recovery U3: 71· tests U1: 110· tests, CMRR (FDU) U3: 137· tests, Distortion (FDU) U3: 134· tests, FDU U3: 124· tests, Gain&Phase U3: 129· tests, LT428 IM: 149· tests, Noise U3: 126· tests, Offset U3: 128· tests, Pulse (FDU) U3: 140· tests, Resistance U3: 124

Instruments· Colour U1: 68· Show/hide U1: 68

Interfacing· source controller U2: 81

Internal· clock U1: 54· time break (SEGD) U2: 21

Interpolation U1: 360· sample U3: 181

Irregular· LT428 layout IM: 148, IM: 150

JJBOD FC U1: 40Julian

· day, backup setup U1: 57Julian day (SEGD) U2: 13

KKit

· tools TM: 14

LLab

· distance to, alarm U1: 244Label

· properties U1: 247Landscape

· plotter U1: 358Language

· help U1: 18Lat. Long

· initial line (SPS) U2: 46, U2: 57· scale factor (SPS) U2: 46, U2: 57

Lat. of standard parallel(s) (SPS) U2: 45, U2: 57

LAUL428· cable replacement TM: 23· connectors IM: 223· disassembly instructions TM: 24· Power supply IM: 121· reassembly instructions TM: 25


Index

· spacing IM: 122LAUR

· disassembly instructions TM: 36· reassembly instructions TM: 37

LAUX428· connectors IM: 224, IM: 225· disassembly instructions TM: 30· Power supply IM: 121· reassembly instructions TM: 31

Layer· rename (Positioning) U1: 222· show/hide (Positioning) U1: 222

Layout· LT428 IM: 137· setup U1: 86

LCI· address U1: 40· changing U1: 38

Leak· testing TM: 61

Leakage· error U1: 101· error (SEGD) U2: 30· limit (SEGD) U2: 30· Sensor test U1: 113· test U3: 151· Test circuitry (LAU) U1: 101· Test limit U1: 84· value (SEGD) U2: 30

Length· record (SEGD) U2: 22· record, process type U1: 140· time, plotter U1: 360· Zeroing (noise) U1: 172· Zeroing Taper (noise) U1: 171

Level· auto, vib drive U1: 311

Licence· code, entering U1: 40· information about U1: 32· LT428 IM: 129· Plotter U1: 41

Lift· up delay U1: 312

Limits (see Test limits)

Line· check U1: 116· data rate U3: 199· Generic U1: 98· mapping to a logical line U1: 105· name (SPS) U2: 51, U2: 52, U2: 65,

U2: 69, U2: 70· Nb Inc, LT428 IM: 136· number U1: 80· number format (SPS) U2: 46, U2: 58· socket, replacing TM: 54· splitting U1: 90· Test, LT428 IM: 134· troubleshooting U1: 117

LINE connector· LAUX IM: 224

Linear· basic sweep signal U1: 271· Phase U1: 53· phase filter U3: 30

Link· examples IM: 118· Number of FDUs, update LT428)

IM: 164Listening

· time U1: 140Live seis traces, number of U2: 19Load

· Thresh U1: 174Loading

· system parameters U1: 328Local

· acquisition U1: 299· disk U1: 40· ellipsoidal model U1: 212· network IM: 20· user U1: 19

LOG· dB/Hz U1: 272· dB/octave U1: 275

Log in· connecting to server U1: 18· installing server software IM: 46· name U1: 19

Logical


Index

· line mapping U1: 105Long. of central meridian (SPS) U2: 46,

U2: 57Look

· Automatic U1: 160· automatic U1: 100· DSD U1: 296· manual U1: 100· properties U1: 100· sensors U1: 67, U1: 68

Loop· servo control U1: 310

Loss· Fibre Optics repairs TM: 115

Low· box, detour U1: 92· channel, detour U1: 93· drive level U1: 311· SN, detour U1: 93· stacks, number of U2: 34· Trace U1: 172· Trace Percentage (SEGD) U2: 21· Trace Value U1: 172· Trace Value (SEGD) U2: 21

Low-cut· Filter frequency (SEGD) U2: 18· Filter slope (SEGD) U2: 18· filter, plotter U1: 357· Playback filter U3: 18

LRU· Desensitization IM: 177· disassembly instructions TM: 43· Frequency IM: 174· Half-duplex IM: 173· reassembly instructions TM: 44

LT· Line Nb IM: 135· Position IM: 133, IM: 135· Rcv Nb IM: 136· Sensor Type Nb IM: 137

LT428· connecting IM: 131· Exec Line Test IM: 134· Exec Transverse Test IM: 134· Field test IM: 150

· Getting started IM: 129· Instrument test IM: 149· main menu IM: 132· Power-on IM: 129· results IM: 155· running Line tests IM: 142· running Transverse tests IM: 152· Save Rcv Tilt model IM: 148· Self-test IM: 130· Set general parameters IM: 133,

IM: 137· Set LT position IM: 133, IM: 135· Set Test Limits IM: 133, IM: 139· Tap test IM: 134, IM: 161

LTO address, changing IM: 80

MMAC address U1: 43MACHA U2: 91Macha blaster U1: 43Maintenance

· field electronics TM: 11Management

· sessions U1: 31· time U1: 54

Manual· Look U1: 100· noise editing U1: 173· shooting U1: 160

Manual/Auto· noise editing threshold U1: 173· VE432 U1: 295

Manufacturer’s· code (SEGD) U2: 13· serial nb (SEGD) U2: 13

Map grid· easting (SPS) U2: 51, U2: 66· northing (SPS) U2: 51, U2: 66

Mapping· line U1: 105

Marker· increment U1: 90· Line Layout setup U1: 86

Marking, stop U1: 93


Index

Mass· acceleration, monitoring U1: 289· velocity, monitoring U1: 289

Max· number of FDUs IM: 122· of max, Aux (SEGD) U2: 22· of max, Seis (SEGD) U2: 22· speed U1: 245· speed, scale U1: 216

Media· copy U2: 12

Min· High Drive U1: 312· Low Drive U1: 311

Minimum· Phase U1: 54· phase filter U3: 50

Minute of day (SEGD) U2: 13Mode

· display, plotter U1: 359· LT428 display IM: 137· operating U1: 158

Model· ellipsoidal U1: 212· geoidal U1: 212

Monoline U1: 105Mounting

· parts IM: 28Mouse

· Centre button U1: 72Move

· alarm U1: 244MRU U1: 44Multi-component

· recording (SPS) U2: 47, U2: 60Mute

· channel U1: 94

NName

· feature, colour map U1: 248· Log in U1: 19· plotter U1: 43· property, query builder U1: 250

NAS· archiving system U1: 45

NAS system IM: 90· connecting IM: 91· IP address on user network IM: 95· reinstalling IM: 92· user network IM: 91

Navigation· shooting mode U1: 178

Nb· Sensor/Rcv Pt, LT428 IM: 137

Network· DSD U1: 267· DSD, Navigation U1: 178

Next· Plot U1: 343

NFS· server U1: 45

No· move U1: 244· reply U1: 243

No. sub arrays, nom depth (SPS) U2: 64Noise

· Editing U1: 170· editing, setup U1: 169· elimination type (SEGD) U2: 21· Instrument test U1: 111· Sensor test U1: 113· Test limit U1: 84· test record result recovery U3: 73· test, FDU (Instrument) U3: 126· test, Sensor (FDU) U3: 145

Noisy· stacks, number of U2: 34· Trace % U1: 172· trace percentage (SEGD) U2: 21

Nominal towing depth U2: 64Normal

· acquisition U1: 315· mode, LT428 display IM: 137

Normalization· plotter U1: 355

Notch U1: 357· frequency (SEGD) U2: 18· playback filter U3: 18


Index

NTP· server U1: 54

Num· Sensor Type, LT428 IM: 137

Number of· Auxes (SEGD) U2: 19· blocks of General Trailer (SEGD)

U2: 15· channel sets per record (SEGD) U2: 14· channels (SPS) U2: 47, U2: 59· channels in this channel set (SEGD)

U2: 17· dead Seis traces (SEGD) U2: 19· DPG modules U1: 42· FDUs between LAUs, max IM: 122· FDUs in link, LT428 IM: 164· geophones per trace U3: 172· live Seis traces (SEGD) U2: 19· plotters U1: 43· sample skew 32 byte extensions (SEGD)

U2: 14· samples in trace (SEGD) U2: 19· samples per trace (SEGD) U2: 27· Seis traces (SEGD) U2: 19· splices, Fibre Optics TM: 115· stacks low (SEGD) U2: 34· stacks noisy (SEGD) U2: 34· subscans exponent (SEGD) U2: 17· traces (SEGD) U2: 19· windows (SEGD) U2: 21· windows, noise editing U1: 171

Numeric· view, Line window U1: 77· view, normal acquisition,VE432

U1: 319Nunits, len, width (SPS) U2: 48, U2: 49,

U2: 61, U2: 62Nut

· wing, replacing TM: 53Nyquist U1: 53

OObserver

· comments, setup U1: 175· privileges U1: 30

Off· Line U1: 58

Offset· removing U3: 171· test U3: 128· test, Sensor U3: 147· to coord. location (SPS) U2: 45,

U2: 55On

· Line U1: 58Open

· session U1: 17Operating

· mode U1: 158Operation

· table U1: 133Options

· Slip-sweep U1: 184Orientation

· LT428 IM: 144· plotter page U1: 358

Output· Dump U1: 142· stack U1: 142

PPage

· setup, plotter U1: 358Parallel

· geophone U3: 173Parameters

· loading (Log) U1: 327· saving (Log) U1: 327· system, editing U1: 327

Parts· FDU, spare TM: 16· LAUL, spare TM: 22· LAUX, spare TM: 29

Password· expiry date U1: 30· opening a session U1: 19

Patch· client IM: 63· server IM: 52


Index

Path· colour U1: 76

PC· Handheld, installing IM: 103

Peg (see Topographic stake)Peripherals

· Install setup U1: 42Permission U1: 30Phase

· angle (SEGD) U2: 16· Control (SEGD) U2: 16· error (Instrument test) U1: 112· Linear U1: 53· Minimum U1: 54· test, FDU U3: 129

Pilot· Aux channel U1: 143· basic signal U1: 286

Pilot length (SEGD) U2: 22Playback

· filters U3: 17Plot U1: 358

· abort U1: 344· Again U1: 343· Next U1: 343

Plotter· AGC U1: 354· ethernet, installing IM: 68· licence U1: 41· mode, display U1: 359· name U1: 43· number of U1: 43· processing U1: 354· scaling U1: 356· type U1: 43

Plug· cleaning IM: 114, TM: 63· process type, FO U1: 140

Plug, FM4· ST+ cable TM: 79· WPSR cable TM: 84

Point· Number (Marker) U1: 89

Point Code· FDU channels U1: 82

· SPS U2: 51, U2: 65Point Depth (SPS) U2: 51, U2: 65Point Index

· SPS U2: 51, U2: 52, U2: 65, U2: 69Point number

· SPS U2: 51, U2: 52, U2: 65, U2: 69Point record

· description (SPS) U2: 65· specification (SPS) U2: 51

Polarity· FDU input IM: 222· SEGD U2: 14

Portrait· plotter U1: 358

Pos. proc. contractor (SPS) U2: 45, U2: 55

Positioning· contractor (SPS) U2: 45, U2: 55· layers U1: 207

Post-plot date of issue (SPS) U2: 45, U2: 54

Power· connector, LAUL428 IM: 223· connector, LAUX IM: 224· socket, replacing TM: 56

Power on· LT428 IM: 129

Power supply· FDU IM: 121· LAUL IM: 121· LAUX IM: 121

Power-off· Line, LT428 IM: 145

Power-on· Line, LT428 IM: 145· test, LT428 IM: 145· Transverse, LT428 IM: 153

P-P bar/m,prim/bubble (SPS) U2: 64Preamplifier

· 0 dB gain U3: 87· 12 dB gain U3: 116

Prestack within field units (SEGD) U2: 21

Preview· colour mapped attributes U1: 248


Index

Privileges U1: 30Process

· Type setup, generating U1: 152· type, Log shooting setup U1: 334· type, overview U1: 139· Type, SEGD U2: 21· Type, setup U1: 156

Processing· capacity U3: 199· Crossline spacing, plotter U1: 356· filter, plotter U1: 357· Geographic AGC, plotter U1: 355· Inline spacing, plotter U1: 356· Normalization, plotter U1: 355· plotter U1: 354· Time, exponential U1: 355· Window length (AGC) U1: 355· Wz velocity, plotter U1: 355

Project code and description (SPS) U2: 46, U2: 58

Projection U1: 252· type (SPS) U2: 45, U2: 56· type, setup U1: 211· zone (SPS) U2: 45, U2: 56

Projection Type setup· Projection U1: 252

Properties· in graphic view, Line U1: 74· Look, Line U1: 100· object label U1: 247

Property· name, query builder U1: 250

Protocol· source controllers U2: 81

Pseudorandom· basic sweep signal U1: 278

Pulse· basic sweep signal U1: 277· test, FDU U3: 140

QQ200 IM: 127

· Backup IM: 110· Battery IM: 106

· connecting IM: 131· Getting started IM: 129· Installing IM: 107· quick guide IM: 104· Reinstalling IM: 111

QC· choice, vib U1: 292· data (How to view) U1: 73· extended, vib U1: 292· limits, vib U1: 291

Quadrant bearing of H256 (SPS) U2: 46, U2: 58

Quality· COG radius threshold U1: 213· Vib position accuracy U1: 215· warning setup U1: 213

Quality Control· check records (SPS) U2: 50

Query· add to U1: 251· builder U1: 250

RR,S,X file quality control (SPS) U2: 50Radio

· delay U1: 309· delay, measuring U1: 307· Delay, VE432 U1: 305· management, vib U1: 288

Radius· alarm, distance to camp U1: 244· alarm, distance to recording unit

U1: 244· shooting setup, Log U1: 334

Random· basic sweep signal U1: 278

Rate· refresh U1: 26· sample U1: 52

Raw· Impulsive Stack process type U1: 147· process type, Correlation U1: 148· servo control U1: 311· Vib Stack process type U1: 151


Index

Rcv· Nb Increment, LT428 IM: 136

Ready· fleet U1: 166

Reassembling· FDU TM: 18· LAUL TM: 25· LAUR TM: 37· LAUX TM: 31· LRU TM: 44· TFOI TM: 106· TREP TM: 51

Receiver· code (Rx) tables (SPS) U2: 48· index (SPS) U2: 52, U2: 70· line number (SEGD) U2: 27· point easting (SEGD) U2: 28· point elevation (SEGD) U2: 28· point index (SEGD) U2: 27· point northing (SEGD) U2: 28· point number (SEGD) U2: 27· section U1: 81· section, marking U1: 88· Tilt model, LT428 IM: 148· Type Layout, LT428 IM: 137

Record· disk, setup U1: 57· identification (SPS) U2: 51, U2: 52· Instrument tests U1: 108· length (SEGD) U2: 22· length, Intrument tests U1: 110· length, process type U1: 140· test result recovery U3: 71· type (SEGD) U2: 14

Record length· SEGD U2: 14

Recovering· instrument test records U3: 71

Reference· resistors, calibration U3: 85· signal, DSD U1: 289· voltage U3: 87· voltage, calibration U3: 85

Refraction· delay, process type U1: 141· delay, SEGD U2: 20

Refresh· rate U1: 26

Registering· user U1: 29

Relation record· description (SPS) U2: 69· specification (SPS) U2: 52

Remote· network IM: 21, IM: 22, IM: 23· user U1: 19· user, installing IM: 56

Rename· layers (Positioning) U1: 222

Rendering· global, plotter U1: 359· setup, plotter U1: 358

Repairing· ST cable TM: 64· ST+ cable TM: 64· WPSR cable TM: 70

Replacing· cable, LAUL TM: 23· cable, TFOI TM: 99· connector, Fibre Optics TM: 107· FDU connector TM: 53· ground wing nut TM: 53· indicators TM: 59· Line & Trans sockets TM: 54· Power socket TM: 56· TFOI board TM: 105· XDEV sockets TM: 57

Reply· alarm U1: 243

Report· generate, query U1: 251

Repository U1: 40Reset

· queries and classification U1: 249Resistance

· error (SEGD) U2: 29· high limit (SEGD) U2: 29· input U3: 91· low limit (SEGD) U2: 29· Sensor test U1: 113· test network U3: 100


Index

· test, FDU U3: 124· test, Sensor U3: 148· value (SEGD) U2: 29

Response, Channel filter U3: 29Retrieval

· Wireline telemetry U1: 59Return

· Pilot U1: 289· signal, DSD U1: 288· sweep, vib U1: 289

Reversed· Marking option U1: 90

Revision· SEGD U1: 56

Revision Number (SEGD) U2: 15Right

· click, Line window U1: 74Role U1: 30Running

· Line tests, LT428 IM: 142· Transverse tests, LT428 IM: 152

SS N (serial number)

· detour U1: 93Sample

· conversion to mV U3: 169· int. Record Len. (SPS) U2: 47· int., Record Length (SPS) U2: 59· interpolation U3: 181· Rate U1: 52· Rate, LT428 IM: 137· skew extensions, number of U2: 14· skew, SEGD U2: 26· to mV conversion factor U2: 34

Sample Rate· SEGD U2: 19

Samples· in trace, number of U2: 19· per trace, number of U2: 27

Save· Rcv Tilt Model, LT428 IM: 148· Thresh U1: 174

Saving

· results, LT428 IM: 158· system parameters U1: 328

Scale· factor (SPS) U2: 46, U2: 57

Scaling· plotter U1: 356· system U1: 33

Scan Type· Header (SEGD) U2: 17· Number (SEGD) U2: 26· per record (SEGD) U2: 14

Sealing TM: 61Searching

· LT428 results IM: 157Second

· Notch Frequency (SEGD) U2: 18· of minute (SEGD) U2: 13

SEGD· Code U1: 84· format U2: 11· revision, choosing U1: 56· setup U1: 56· Trace Blocking U1: 256

Seis traces, number of U2: 19Seismic

· datum (SPS) U2: 51, U2: 66· instrument header records (SPS) U2: 59· receiver header records (SPS) U2: 61· setup, Operation U1: 158· source header records (SPS) U2: 62· trace scaling U1: 356

Seismonitor U1: 71· gain U1: 71· Sensor test U1: 115

Select· vib (Look) U1: 296

Selecting· in graphic view U1: 72· traces to plot U1: 351

Selection· create U1: 251

Self-test· LT428 IM: 130

Senior· Observer, privileges U1: 30


Index

Sensor· Coulour code U1: 66· Distortion test U1: 114· Leakage test U1: 113· Noise test U1: 113· num/Rcv pnt, LT428 IM: 137· Resistance test U1: 113· Seismonitor U1: 115· sensitivity (SEGD) U2: 32· show/hide U1: 66· test limits U1: 83· tests U1: 112· tests, CMRR U3: 156· tests, Distortion U3: 161· tests, FDU U3: 145· tests, Impulse U3: 159· tests, Leakage U3: 151· tests, Look U1: 100· tests, Noise (FDU) U3: 145· tests, Offset U3: 147· tests, Resistance U3: 148· tests, Tilt U3: 154· Tilt model U1: 114· Tilt test U1: 113· Type, LT428 IM: 137

Sensor Type· FDU channels U1: 83· Number (sensor tests) U2: 28· SEGD code U2: 27

Sequencer· Shallow U2: 89

Sequential· time, plotter U1: 359· trace, plotter U1: 359

Serial· number, detour U1: 93

Series· geophones U3: 173

Server· administration U1: 29· FTP U1: 45· log on to U1: 18· NFS U1: 45· NTP U1: 54· software, installing IM: 44· start/stop U1: 16

Servo· input U1: 310· setting U1: 310

Session· manager U1: 31· opening U1: 17

Set· channel, number per record U1: 56· DSD U1: 301· Servo U1: 310

Sets, channel U2: 14Settings

· browser U1: 17· help U1: 18

Setup· Crew, vibrators U1: 266· Observer comments U1: 175

SFL· Spread First Line U1: 155

SFN· Spread First Number U1: 155

SGDS U2: 92SGS

· shooting system U1: 42Shallow

· Sequencer U2: 89Shallow blaster U1: 42Shock

· mount parts IM: 28Shock-mount

· Blade 2000 IM: 29· Blade 2500 IM: 28· Cartridge drive IM: 72

Shooter U1: 176Shooting U1: 176

· Navigation mode U1: 178· setup, Log U1: 333· system U1: 42· systems, interfacing U2: 81

Shortcut· Line window U1: 74

Shot· automation U1: 159· Depth, charge len. (SPS) U2: 50· depth, charge len. (SPS) U2: 63


Index

· Id U1: 154· Id, Log shooting setup U1: 334· increment U1: 163· number (SEGD) U2: 19· starting U1: 135

ShotPro· install U1: 42· interfacing U2: 85

Show· layer (Positioning) U1: 222

Signal· return sweep U1: 289

Simultaneous mode U3: 199Single

· mode, recording specifications U3: 199Size

· external header U1: 56· vert. stk fold (SPS) U2: 49

Size, vert. stk fold (SPS) U2: 62Skew, sample, number of extensions

U2: 14Skip

· receiver points (detour) U1: 103Skipped

· lines (spread description) U1: 99Slave

· 428XL U2: 82· DPG U1: 267

Slip-sweep U1: 184· mode used (SEGD) U2: 22

Snaking U1: 90· FDU U1: 104

Software· e428, licence U1: 40· Handheld PC, installing IM: 103· patch (client) IM: 63· patch (server) IM: 52· updating U1: 126· version (SEGD) U2: 22

Software, installing· GoBook IM: 107· server IM: 44· Solaris IM: 36

Soil, drill method (SPS) U2: 50, U2: 63Solaris installation IM: 36

Source· aux nb (SEGD) U2: 22· code (Sx) tables (SPS) U2: 49· controller, time management U1: 54· easting (SEGD) U2: 22· elevation (SEGD) U2: 22· Explosive U1: 163· Line U1: 155· Line Number (SEGD) U2: 16· northing (SEGD) U2: 22· Point Index (SEGD) U2: 16· Point Number (SEGD) U2: 16· point setup, generating U1: 156· point, setup U1: 154· Receiver U1: 155· Set Number (SEGD) U2: 16· type, setup U1: 162

Spacing· crossline (AGC) U1: 356· FDU IM: 122· inline (AGC) U1: 356· LAU IM: 122

Spare· FDU parts TM: 16· LAUL parts TM: 22· LAUX parts TM: 29

Specifications· 428XL U3: 193

Speed· alarm U1: 246· maximum U1: 245· maximum, scale U1: 216

Spike· editing U1: 192

Split· line U1: 90

Spread· absolute U1: 96· generic U1: 97· number (SEGD) U2: 19· setup U1: 95· SFL U1: 155· SFN U1: 155· type U1: 155· type (SEGD) U2: 20

ST cable


Index

· Repairing TM: 64ST+ cable

· Repairing TM: 64Stack

· Correlation after, process type U1: 149· Correlation before, process type

U1: 148· Impulsive, process type U1: 147· Output button U1: 142· Vibroseismic, process type U1: 151

Stacking Fold· SEGD U2: 21

Stacks, number of· Low U2: 34· Noisy U2: 34

Stake (see Topographic stake)Standard

· process type U1: 140Start

· colour map scale U1: 248· time, plotter U1: 360

Starting· 428 server U1: 16

Static correction (SPS) U2: 51, U2: 65Statics U3: 181Statistics

· VE432 U1: 313Status

· codes U1: 321· DSD, get U1: 288

Step· negative U1: 182· Vibroseismic source U1: 165

Stop· button, Operation U1: 135· Marking U1: 93

Streamer cable number (SEGD) U2: 18String

· gain, geophone U3: 173· group, geophone U3: 177· impedance, geophone U3: 173· wiring, geophones U3: 178

Subarrays, number of U2: 64Subscan exponent U2: 17Support

· customer U1: 49Surface

· elevation, reference U1: 212· elevation, SPS U2: 51

Surface elevation· SPS U2: 66

Survey· description U1: 80· setup U1: 79

Swath· backup setup U1: 57· first line (SEGD) U2: 19· first number (SEGD) U2: 19

Sweep· basic signal (Acquisition type) U1: 286· freq start, end (SPS) U2: 49· frequency start,end (SPS) U2: 63· length (SEGD) U2: 22· return signal U1: 289· type, length (SPS) U2: 49, U2: 63

Sync· high line U1: 287

Syntax (see Description)Synthetic

· file syntax U1: 123· Signal type U1: 123

System· scaling U1: 33· shooting U1: 42

System tools IM: 51· USB key management IM: 51

TT0

· mode U1: 294· Repeat Times U1: 293· setup U1: 293

Table· operation U1: 133

Tap· test, LT428 IM: 134, IM: 161

Tape· bypass U1: 259· copy U2: 12


Index

· drive address3592 IM: 84FUJI 3x90, changing IM: 74FUJI 3x90, displaying IM: 75LTO IM: 80

· drive, install U1: 45· drives, supported IM: 73· Label U1: 255· label (SEGD) U2: 22· Number U1: 255· number of files U1: 256· number, SEGD U2: 22· setup, Export window U1: 255· type, format, density (SPS) U2: 47,

U2: 59Tape/disk identifier (SPS) U2: 45,

U2: 54Taper U1: 269

· length start, end (SPS) U2: 49, U2: 63TB

· window, process type U1: 141· window, SEGD U2: 19

Tb to T0 time (SEGD) U2: 21Test

· Automatic U1: 160· functions U1: 107· functions, FDU U3: 119· generator U3: 91· Instrument, FDU U3: 124· limit

battery U1: 70Continuity U1: 84Leakage U1: 84Noise U1: 84Sensor U1: 83Tilt U1: 84

· limits, LT428 IM: 133, IM: 139· network, Resistance U3: 100· record result recovery U3: 71· Record, type (SEGD) U2: 19· Sensor, FDU U3: 145· setup U1: 107· shortcut (Topographic view) U1: 67,

U1: 68· Spread U1: 109

Tested

· Line Nb, LT428 IM: 136TFOI

· board, replacing TM: 105· cable TM: 99· disassembly instructions TM: 99· reassembly instructions TM: 106

Third Notch Frequency (SEGD) U2: 18Threshold

· COG radius U1: 213· Hold/Var (SEGD) U2: 21· Init U1: 173· Init Value, noise editing U1: 172· Load U1: 174· Save U1: 174· type tables (SEGD) U2: 21· updating (noise elimination) U1: 193

Tilt· error (SEGD) U2: 29· limit (SEGD) U2: 29· Model U1: 114· test U1: 113, U3: 154· Test limit U1: 84· value (SEGD) U2: 29

Time· delay, FTB-SOD (SPS) U2: 47, U2: 60· domain, correlation U3: 166· exponential, plotter U1: 355· Interpolation U1: 360· Length, plotter U1: 360· listening U1: 140· management U1: 54· Sequential, plotter U1: 359· SPS U2: 51, U2: 67· Start, plotter U1: 360

Time break· SEGD U2: 20· window, SEGD U2: 26

TMS428 U3: 84TMU428 U3: 84Tn U1: 276

· basic sweep signal U1: 276To channel (SPS) U2: 52, U2: 69To receiver (SPS) U2: 52, U2: 70Tool

· maintenance, field electronics TM: 14


Index

· System IM: 51· USB key management IM: 51

Tools· ST & ST+ cable repair TM: 64· ST+ FM4 plug replacement TM: 79· STSR FM4 plug replacement TM: 84· WPSR cable repair TM: 70· WPSR FM4 plug replacement TM: 84

Topographic· stake U1: 66· view U1: 64

Total number of traces (SEGD) U2: 19Towing depth U2: 64Trace

· blocking U1: 256· Data block U2: 25· edit (SEGD) U2: 26· Low U1: 172· Noisy percentage U1: 172· Number (SEGD) U2: 26· number of samples in U2: 19· selecting, plot U1: 351· Sequential, plotter U1: 359

Trace Header· Extension (SEGD) U2: 26· Extension Block 1 (SEGD) U2: 27· Extension block 2 (SEGD) U2: 27· Extension block 3 (SEGD) U2: 29· Extension block 4 (SEGD) U2: 30· Extension block 5 (SEGD) U2: 30· Extension block 6 (SEGD) U2: 31· Extension block 7 (SEGD) U2: 33· Extensions (SEGD) U2: 18, U2: 27· SEGD U2: 26

Traces· per inch U1: 359· total number of U2: 19

Traces, number of· Aux U2: 19· Dead seis U2: 19· Live seis U2: 19· Seismic U2: 19

Tracking· box, installing IM: 102· Positioning window U1: 231· vehicle setup U1: 216

Trailer, general U2: 15Trans

· socket, replacing TM: 54Transfer

· to drive, spec U3: 199Transmission

· test IM: 154· test, Line (LT428) IM: 146· troubleshooting U1: 76

Transverse· connector, LAUX IM: 224· data rate U3: 199· test, LT428 IM: 134

Transverse (LT428) IM: 154TREP

· disassembly instructions TM: 50· reassembly instructions TM: 51

Troubleshooting· Line U1: 117· Transmission U1: 76

Type· blaster U1: 42· box, detour U1: 92· Model, Polarity (SPS) U2: 47, U2: 48,

U2: 49, U2: 59, U2: 61, U2: 62· of process (SEGD) U2: 21· of source (SEGD) U2: 19· plotter U1: 43

UUninstalling

· patch (client) IM: 63· patch (server) IM: 52

Unit· serial number (SEGD) U2: 31· type (SEGD) U2: 31

Units· how to select U1: 72· spacing X, Y (SPS) U2: 48, U2: 49,

U2: 61, U2: 62Unselect

· in Line topographic view U1: 72Update

· field U1: 63, U1: 113, U1: 114


Index

Updating· firmware U1: 126· Number of FDUs in link, LT428)

IM: 164Uphole

· time (SEGD) U2: 20· time (SPS) U2: 51, U2: 66

URL· opening a session U1: 19

USB key IM: 51User

· info U1: 55· local IM: 20· registering U1: 29· remote IM: 21, IM: 22, IM: 23

VVA (plotter) U1: 359Values

· query builder U1: 251Var/Hold U1: 173VE432

· functions U1: 295Vehicle

· Tracking box IM: 102Velocity

· baseplate, monitoring U1: 289· mass, monitoring U1: 289· plotter U1: 355

Vertical· datum description (SPS) U2: 45,

U2: 56· Stack (SEGD) U2: 18

Vib· position accuracy U1: 215

Vibrator· QC choice U1: 292· QC limits U1: 291· Radio management U1: 288· T0 U1: 293· type U1: 42· type (SEGD) U2: 16

Vibroseis (SPS) U2: 49View

· Graphic (normal acquisition) U1: 316· Numeric (normal acquisition) U1: 319· numeric, Line window U1: 77· topographic, line U1: 64

Voltage· reference U3: 87

VP· grabbing radius U1: 214· Id U1: 154· to do, increment U1: 165

WWater

· depth (SPS) U2: 51, U2: 66· gun (SPS) U2: 50

Watertightness TM: 61Waypoint

· first U1: 217Weathering thickness (SPS) U2: 50,

U2: 63Wiggle U1: 359Window

· Length, AGC U1: 355· Number of (noise) U1: 171· TB U2: 19· TB, process type U1: 141

Wing· nut, replacing TM: 53

WPSR cable· Repairing TM: 70

Wz Velocity, AGC U1: 355

XXDEV

· connector, LAUL IM: 223· connector, LAUX IM: 225· socket, replacing TM: 57

Xmit· test, Line ( LT428) IM: 146· test, Transverse (LT428) IM: 154

YYear (SEGD) U2: 13


Index

ZZeroed

· channel U1: 94Zeroing

· Length (noise) U1: 172· method (noise elimination) U1: 193· noise editing type U1: 171· Taper Length (noise) U1: 171

Zoom· Line window U1: 73


Index


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