Overview of ADCP “Best Practices”

Report

Overview of ADCP “Best Practices”

ReportMeasuring Discharge with Acoustic Doppler Measuring Discharge with Acoustic Doppler

Current Profilers from a Moving BoatCurrent Profilers from a Moving BoatTechniques and Methods Report Techniques and Methods Report

Chapter 22 of Book3, Section AChapter 22 of Book3, Section A

OverviewOverview Why a Techniques and Methods ReportWhy a Techniques and Methods Report Organization of the reportOrganization of the report Highlight selected topicsHighlight selected topics Changes to existing policyChanges to existing policy Quick-Reference guidesQuick-Reference guides

and other forms and other forms Availability of printed copiesAvailability of printed copies

Why and HowWhy and How COE funded development of two guidance COE funded development of two guidance

reports for ADCP usereports for ADCP use DischargeDischarge Velocity MappingVelocity Mapping

Revised more general COE report to USGS Revised more general COE report to USGS specific T&Mspecific T&M USGS specific policyUSGS specific policy StreamProStreamPro Updated with latest guidanceUpdated with latest guidance

Source of MaterialSource of Material Little “new” informationLittle “new” information Consolidated information from:Consolidated information from:

QA/QC reportQA/QC report OSW Technical MemosOSW Technical Memos ADCP Training ClassesADCP Training Classes Hydroacoustic UpdatesHydroacoustic Updates

Added some changes to guidance based on Added some changes to guidance based on latest experiencelatest experience

Published to allow additional updates Published to allow additional updates without republishing entire reportwithout republishing entire report

OrganizationOrganization Main Body contains guidanceMain Body contains guidance

Predeployment PreparationPredeployment Preparation Field ProceduresField Procedures Office ProceduresOffice Procedures

Appendices contain detailsAppendices contain details Basic ADCP Operational ConceptsBasic ADCP Operational Concepts Collecting Data in Moving-Bed ConditionsCollecting Data in Moving-Bed Conditions Description of Water ModesDescription of Water Modes Beam-Alignment TestsBeam-Alignment Tests Forms and Quick-Reference GuidesForms and Quick-Reference Guides Measurement Review ProceduresMeasurement Review Procedures

PredeploymentPredeployment Understand basic limitations Understand basic limitations

of ADCPof ADCP Apply ADCP limitations to Apply ADCP limitations to

site selection and expected site selection and expected performance in the fieldperformance in the field SedimentSediment Unmeasured areasUnmeasured areas ConfigurationConfiguration CompassCompass

A) Excessive BackscatterA) Excessive Backscatter B) Excessive AttenuationB) Excessive Attenuation

Predeployment – cont.Predeployment – cont. Instrument Quality AssuranceInstrument Quality Assurance

Beam Alignment TestBeam Alignment Test RecommendedRecommended

11stst acquired acquired After factory repairAfter factory repair After firmware or hardware upgradesAfter firmware or hardware upgrades PeriodicallyPeriodically

Detailed procedures in Appendix DDetailed procedures in Appendix D Typically for Rio Grandes and RiverSurveyorsTypically for Rio Grandes and RiverSurveyors

Periodic Instrument ComparisonPeriodic Instrument Comparison

Predeployment – cont.Predeployment – cont. Ancillary EquipmentAncillary Equipment

GPSGPS VTG and GGAVTG and GGA

Echo SounderEcho Sounder Deployments and MountsDeployments and Mounts Other EquipmentOther Equipment

Final Equip Preparation and InspectionFinal Equip Preparation and Inspection Verify all computer connections and Verify all computer connections and

communications before going to the field!!communications before going to the field!!

Checklist in Appendix EChecklist in Appendix E

Field ProceduresField Procedures Site SelectionSite Selection

Maybe the most important thing you do in the Maybe the most important thing you do in the field.field.

Location, shape, velocity, otherLocation, shape, velocity, other Pre-Measurement Field ProceduresPre-Measurement Field Procedures

Set clockSet clock Diagnostic testsDiagnostic tests Speed of sound (temp and salinity)Speed of sound (temp and salinity) Compass calibrationCompass calibration Instrument configurationInstrument configuration

Use wizardsUse wizards

Moving-bed testsMoving-bed tests

Policy ChangePolicy Change

USGS policy (U.S. Geological Survey, 2002b; Oberg and others, 2005) requires that a moving-bed test be conducted prior to making a discharge measurement. In USGS training classes and in Oberg and others (2005), an exception to conducting a moving-bed test with every measurement was allowed if sufficient documentation was providedin the field folder to justify not conducting a moving-bed test. Field experience has shown that sediment transport characteristics can vary greatly for the same discharge, depending on the hydrograph shape, source of runoff, and season of the year. Thus, a moving bed may be detected at a location and discharge where one was not previously detected, or a moving bed may no longer exist at a location and discharge where one was previously detected. Moving-bed conditions also have been observed in low-velocity environments (less than 1 ft/s) and are likely caused by organic material transported by the water. Therefore, to ensure the quality of the data collected, everymoving-boat measurement made with an ADCP must have a recorded moving-bed test. If a site routinely has a moving bed and GPS is always used with the ADCP, a moving-bed test is still required but need only be 5 minutes in length. This requirement supersedes Oberg and others (2005) and various USGS training materials.

Moving-Bed Test Requirements

Moving-Bed Test Requirements

Loop test preferredLoop test preferred Stationary testsStationary tests

WhenWhen If compass calibration is not goodIf compass calibration is not good If bottom tracking cannot be maintainedIf bottom tracking cannot be maintained StreamProStreamPro

HowHow 5-minutes in duration5-minutes in duration

With GPSWith GPS From a tagline or bridge or anchoredFrom a tagline or bridge or anchored

10-minutes in duration10-minutes in duration No GPS from manned or RC-boatNo GPS from manned or RC-boat

These criteria supersede the guidance on stationary moving-bed tests that have been published previously in U.S. Geological Survey (2002b) and Oberg and others (2005).

Field Procedures – cont.Field Procedures – cont. Discharge Measurement ProceduresDischarge Measurement Procedures

No changes to existing guidanceNo changes to existing guidance Step by step quick-reference guides in Step by step quick-reference guides in

Appendix EAppendix E Post-Measurement Field ProceduresPost-Measurement Field Procedures

An 8-pass measurement due to one or more An 8-pass measurement due to one or more transects being >5% from mean does not transects being >5% from mean does not constitute a check measurementconstitute a check measurement

Check measurements are required according to Check measurements are required according to criteria in WSP 2175criteria in WSP 2175

Office ProceduresOffice Procedures Preventive MaintenancePreventive Maintenance

Saves time in the long term!!!Saves time in the long term!!! Data StorageData Storage

Follow office policyFollow office policy Put data on server (usually within 72 hours)Put data on server (usually within 72 hours)

Measurement ReviewMeasurement Review Data-Quality IndicatorsData-Quality Indicators Commonly Observed ProblemsCommonly Observed Problems

Measurement ReviewMeasurement Review

1.1. Field forms complete, understandable, and Field forms complete, understandable, and legible.legible.

2.2. Electronic files backup in field and archived Electronic files backup in field and archived in office.in office.

3.3. Number of transects appropriate and in Number of transects appropriate and in reciprocal pairs.reciprocal pairs.

4.4. ConfigurationConfigurationa)a) Correct and appropriateCorrect and appropriate

b)b) User input agrees with field formUser input agrees with field form

c)c) Edge, top, and bottom extrapolations Edge, top, and bottom extrapolations appropriateappropriate

Measurement Review – cont.

Measurement Review – cont.

5.5. Independent temperature measurement Independent temperature measurement recorded and checked.recorded and checked.

6.6. Salinity measured and recorded.Salinity measured and recorded.

7.7. Moving-bed test recorded and appropriate Moving-bed test recorded and appropriate procedures used.procedures used.

8.8. Slow smooth boat operation.Slow smooth boat operation.

9.9. Edge distance measured, recorded, and Edge distance measured, recorded, and consistent with electronic data.consistent with electronic data.

10.10.Number and location of missing or invalid Number and location of missing or invalid ensembles are acceptable.ensembles are acceptable.

Measurement Review – cont.

Measurement Review – cont.

11.11.Number and location of invalid depth cells Number and location of invalid depth cells are acceptable.are acceptable.

12.12.Top and bottom extrapolation methods have Top and bottom extrapolation methods have been reviewed and are appropriate.been reviewed and are appropriate.

13.13.Measurement computations, including mean Measurement computations, including mean discharge and measurement gage height, discharge and measurement gage height, are correct.are correct.

Missing and Invalid DataMissing and Invalid Data

WinRiver IIWinRiver II

RiverSurveyorRiverSurveyor

Ambiguity ErrorsAmbiguity Errors

Signal AttenuationSignal Attenuation

Beam Impinging on WallBeam Impinging on Wall

Smooth Boat OperationSmooth Boat Operation

WinRiver IIWinRiver II

RiverSurveyorRiverSurveyor

Spikes in StreambedSpikes in Streambed

Bad GPSBad GPS

Appendix A – Basic Concepts

Appendix A – Basic Concepts

Doppler ConceptsDoppler Concepts Narrowband and BroadbandNarrowband and Broadband Computing Velocity in Orthogonal Computing Velocity in Orthogonal

CoordinatesCoordinates Measuring a Velocity ProfileMeasuring a Velocity Profile Computing DischargeComputing Discharge

Appendix B- Collecting Data in Moving-Bed

Conditions

Appendix B- Collecting Data in Moving-Bed

Conditions Cause and Effect of Moving-BedCause and Effect of Moving-Bed Methods to Indentify a Moving BedMethods to Indentify a Moving Bed

More detail than in main body of reportMore detail than in main body of report Stationary, no GPSStationary, no GPS Stationary, with GPSStationary, with GPS LoopLoop

Methods to Account for Moving-Bed EffectsMethods to Account for Moving-Bed Effects GPSGPS Loop methodLoop method Multiple moving-bed test methodMultiple moving-bed test method Mid-section methodMid-section method Azimuth methodAzimuth method

Appendix C – Description of Water Modes

Appendix C – Description of Water Modes SonTek/YSI RiverSurveyorSonTek/YSI RiverSurveyor TRDITRDI

Rio GrandeRio Grande 11 5/115/11 1212

StreamProStreamPro 1212 13, C, Low-Noise13, C, Low-Noise

Appendix D – Beam-Alignment Test

Appendix D – Beam-Alignment Test

Detailed instructions Detailed instructions and criteria for and criteria for conducting a beam conducting a beam alignment testalignment test

Typically only Typically only applied to:applied to: Rio GrandeRio Grande RiverSurveyorRiverSurveyor

Appendix E – Forms andQuick-Reference GuidesAppendix E – Forms andQuick-Reference Guides

Rio Grande Quick SheetRio Grande Quick Sheet

RiverSurveyor Quick SheetRiverSurveyor Quick Sheet

Appendix F –Measurement Review

Guides

Appendix F –Measurement Review

Guides

AvailabilityAvailability PDF version available nowPDF version available now

http://pubs.usgs.gov/tm/3a22/ Linked from Linked from http://hydroacoustics.usgs.gov/

Printed versionPrinted version 3-hole punch, loose leaf3-hole punch, loose leaf In printing now, available in a couple of monthsIn printing now, available in a couple of months

Announcement memo will be accompany Announcement memo will be accompany printed version.printed version.

QuestionsQuestions