GPHYS, Obs. de Paris - 23 juin 2010 1

■Objectives

■Organisation : mission J2 <-> CMS

■Principe

■Data flow

■Measures & SLR stations

■Results

■Web-outreach

■Current experiments

■To be developed

T2L2 resultsfrom the Sci. Mission Center

P. Exertier, OCA-CNRS-UNS

GPHYS, Obs. de Paris - 23 juin 2010 2

Objectives

I-Data Processing

IIa-Time Transfer : - ground-board : 50 ps @ 1 sec then 5-10 ps @ 30 sec- ground-ground : common view or not (-> see the 1-one way calibration to be

deployed)

IIb-Time scale : OUS <-> SLR stations (UTC) => dates DORIS ~0.3µsecIIIa-Orbitography :

- DORIS - T2L2 : monitoring of USO frequency ~10-12 / ±10 ps @10 sec- Laser - T2L2 : re-estimation of 1-way links (tB-tS à 10 ps)

IIIb-Energy budget & atmosphere :- Laser : energy measured on board -> atmosphere and ground instrument- tropospheric correction: 1-way measures < 15 deg elevation

IV-Fundamental Physics

GPHYS, Obs. de Paris - 23 juin 2010 3

Principle

LRA

tSsta

tRsta = tSsta+ dtTR

dtTR

tBsat

UTC

tBsat

tGPSsat

dtT

dtTR

USO

tTsta , dtTR , tRsat: measured quantities= « triplet »

(dtT is computed from dtTR)

tTsta

XA = tS + tR

2− tB + τRelativity + τ Atmosphere+ τ Instrument

GPHYS, Obs. de Paris - 23 juin 2010 4

Payload on the Jason2 satellite

� Masse : 8 kg (électronique) + 1.1 kg (optique)

� Consommation : 42 W

� Volume : 270x280x250 mm3 // Ø 30x95 // Ø62x100 Earth

GPHYS, Obs. de Paris - 23 juin 2010 5

Principle, 2

On-board oscillator noise σx(0.1 s)

On-board oscillator noise sx(t3) :

20 ps @ 100 s ; 500 ps @ 1000 s ; 20 ns @ 10 000 s

( ) ( ) 10.2 223142

x

+− τ×=τσ

GPHYS, Obs. de Paris - 23 juin 2010 6

Expected stability & noises

■ Validation of the optical link :

�

� for ττττ > 10000 s

� accuracy < 100 ps

σ y(τ) = 0.4 10−13τ−1/ 2

σ x2 τ( ) = 28.10−12 × τ−1/ 2( )2

+ 17.10−15 × τ +3 / 2( )2 τ0 = 0.1 s

0.1

1

10

100

1000

0.1 1 10 100 1000 10000 100000 1000000 10000000 100000000

ττττ (s)

σσσσx(ττττ) (ps)

Atmosphère Dateur Sol

Géométrie Dateur Sol - Retour

OUS Dateur Bord

S/S vues communes

GPHYS, Obs. de Paris - 23 juin 2010 7

Organisation

Groupe CAL/VAL

CMI(instrument)

Formats

ILRSInternat. Laser Ranging Service

Mises au pointParamètresObservations

Stations laser

DORISOUS

Orbitographie

Obs. de ParisCampagnesACES/Pharao

CollaborationsGroupe de Travail T2L2

Publications/Présent.Web

Diffusion

CMSCentre de Mission Scientifique

Mission JASON-2

OCA

CNES & NASA

GPHYS, Obs. de Paris - 23 juin 2010 8

Data (/day) : GROund (laser telemetry & station parameters)BOArd (T2L2 : 12345678-123456789012)

Levels of processingLev. 1 : Board & GroundLev. 2 : orbit -> « O-C » telemetry, Triplets

ResultsLev. 3 : Time transfer(s)

(model instrumental, filtering,...)

gr-ground ... ground-boardstations & OUS DORIS

Data flow

GPHYS, Obs. de Paris - 23 juin 2010 9

SLR Stations

STATION CNTRY CONTACT LASER TIMER CLOCKS GPS TIME

MLRS USA Jerry Wiant 200ps UTT Quartz TACHERSTMONCEUX UK Graham Appleby kHz 10ps + 20ps Thales gps + Maser DatumZIMMERVALD Suisse Werner Gurtner 100 Hz 30ps Riga Quartz True TimeGRAZ Autriche Georg Kirchner kHz 10ps + 20ps Tales Quartz HPMATERA Italie Giuseppe Bianco 40ps Honeywell T. Cesium + Maser True TimeLVIV Ukraine Andrij Bilinsky 150ps Riga Rubidium MotorolaBOROWIEC Pologne Stanislaw Schillak 40ps Maser BorowiecHARTEBEESHOEK Afrique S Johan Bernhardt 200ps Rubidium TrimbleURUMQI (mobile) Chine Guo Tangyong 30ps QuartzKUNMING Chine Xiong Yaoheng 200ps gps AbsoluteSHANGHAI Chine Yang Fumin kHz 10ps + 50ps Riga Rubidium SymmetriconCHANGCHUN Chine You Zhao kHz 20ps +200ps Riga Quartz HPSIMOSATO Japon Michihiro Suzuki 100ps non Cesium True TimeKOGANEI Japon Hiroo Kunimori 50ps +2.5ns EOS Cesium True TimeYARRAGADEE Australie Vince Noyes 200ps Rub. + Cesium CNSMOUNT STROMLO Australie Chris Moore 10ps + 3ns EOS Quartz + cesium True TimeROA Espagne Jorge Garate 100 ps 5 Hz RubidiumWETTZELL Alemagne Ulrich Schreiber 20 ps Thales Masers + CesiumMeO-GRASSE France Etienne Samain 20 ps Thales Cesium + MaserFTLRS-GRASSE France Francis Pierron 30 ps Thales Cesium + Maser DatumPotsdam 2 & 3 Alemagne Ludwig Grunwalt 35 ps Riga RubidiumMaidanak 1 & 2 Russie Nat. Parkhomenko 100 ps 5 Hz Riga Rubidium

GPHYS, Obs. de Paris - 23 juin 2010 10

Measures & SLR network■ 47 Stations

■ 34 fired Jason

■ 24 ±±±±regularly on Jason2

GPHYS, Obs. de Paris - 23 juin 2010 11

Level I

Re-format of SLR Full Rate data- which SLR stations, technolog. parameters, pass & measures

Datation of board dates (12345678 - 123456789012 -> June, 23, 16h 15’ 00’’0.1234567...)

- filtering of (GPS) PPS -> USO (DORIS) long term monotoring- datation UTC (synchro. with board time to ± 0.2-0.4 µsec)

Correlation between both board and ground data files -> « triplets »- first statistics

-> history

-> history

-> history

GPHYS, Obs. de Paris - 23 juin 2010 12

First detections by T2L2 (June 210)

GPHYS, Obs. de Paris - 23 juin 2010 13

Id

GPHYS, Obs. de Paris - 23 juin 2010 14

Level II

Computation of the range station-T2L2 :- SLR range (dt -ToF: station-LRA-station) -> dt station-T2L2 : Sagnac

(30 ns), attitude (centre of mass, sat - LRA - T2L2, 0.3 ns)

Comparisons (/day) range and MOE-Jason2 ephemeris, with ITRF-2005, Earth rot., tropo., ... :

- O-C : ± 3-5 cm (> 100ps)- comptutation of true-false measures (if pulse times without echoes)

Triplets (with true-true and true-false)

Indic. for measures & corrections 0

1,...

dta-rO

11

111

dta-rCtBordtSol

GPHYS, Obs. de Paris - 23 juin 2010 15

Orbitography

GPHYS, Obs. de Paris - 23 juin 2010 16

Level III

■ Filtering of range data (-> decreasing the noise) :

� 15sec (recomm. of ILRS / Normal Pts)

� Re-estimation of true-false triplets (filtered range)

■Instrumental model

� corrections of time walk (diode), and attitude (energie # BOLI & BONL)

� pb of laser trains

■Treatment of ground-space tt

� outilers to 1-4 ns, /analysis of the local distribution -> sigma « cible »

� pb of the expected performances of ground clocks

� 10-30 sec (recomm. DORIS)

� editing of quantities : df/f, synchron. OUS - UTC station

■Time Transfer(s)

� ground-board, calcul systématique

� ground - ground common / non comm. view

GPHYS, Obs. de Paris - 23 juin 2010 17

Filtering (SLR range)

GPHYS, Obs. de Paris - 23 juin 2010 18

Instrumental correction (time walk)

■Distribution without energy compensation

■Dissymetrie due to the energy distribution

■ σσσσ = 67 ps rms

GPHYS, Obs. de Paris - 23 juin 2010 19

Time walk and attitude corrections, 2

GPHYS, Obs. de Paris - 23 juin 2010 20

Ground-space tt (outliers and ref. clocks)

GPHYS, Obs. de Paris - 23 juin 2010 21

Example of ground-space tt (Meo /Cesium)

GPHYS, Obs. de Paris - 23 juin 2010 22

MeO /Maser (TS4) from May, 20 2010

GPHYS, Obs. de Paris - 23 juin 2010 23

Ground-ground time transfer (Grasse)

GPHYS, Obs. de Paris - 23 juin 2010 24

2: Grasse FTLRS<->MeO

GPHYS, Obs. de Paris - 23 juin 2010 25

Web

■T2L2, site on www.oca.eu

■english, french

■ information pages (project, team, objectives, ...)

■dynamical pages

� selections of macro-data from small history files

� tables /station or /period of time

� tables for on board data, ground SLR data available and triplets

� time transfer : from ground to space : residuals and time stability

� « from ground to ground : will present the raw result of time transfers between a couple of SLR stations, at 1 ns.

GPHYS, Obs. de Paris - 23 juin 2010 26

Conclusion

■Precision /expected performances

■Relations with SLR stations and ILRS -> data & campaigns

■Campaigns of tt (juin-juillet 2010)

� common view : Obs. de Paris - Grasse - Borowiez

� non common : Koganei (Japon)

■Relations to be enlarged with the DORIS community

■Orbitography (1-way), and inter-operability T2L2-laser-DORIS

■Fundamental physics

■ACES/Pharao : a sinergy ?

■Colloques and articles (ASR, EFTF, PTTI, IDS, SWT Jason, ...)

GPHYS, Obs. de Paris - 23 juin 2010 27

Thank You

GPHYS, Obs. de Paris - 23 juin 2010 28

Example (history)

histo_Past_20091001:TRIP 7308, 1 112 0 64.0 0.5370 97 0.000099 1730 30.81

histo_Past_20091008:TRIP 7308, 1 476 0 62.4 0.5541 445 0.000108 6410 50.27

histo_Past_20091013:TRIP 7308, 1 238 0 56.0 0.3196 217 0.000126 3226 0.00

histo_Past_20091013:TRIP 7308, 2 693 0 28.2 0.2650 630 0.000153 2787 0.00

histo_Past_20091013:TRIP 7308, 3 575 0 76.3 0.2400 543 0.000117 5260 0.00

histo_Past_20091010:TRIP 7828, 1 107 81 4.0 -0.1350 66 0.000745 579 41.64

histo_Past_20091010:TRIP 7828, 2 291 108 24.6 16.9765 47 0.001204 2313 44.78

histo_Past_20091010:TRIP 7828, 3 97 31 11.7 16.9846 47 0.001009 702 34.33

histo_Past_20091012:TRIP 7828, 1 37 28 1.3 16.9935 8 0.001264 840 49.51

histo_Past_20091007:TRIP 7845, 1 3 1 0.4 -0.1766 0 0.000000 268 52.53

histo_Past_20091007:TRIP 7845, 2 11 1 1.1 -0.1733 10 0.000075 2576 42.78

histo_Past_20091009:TRIP 7845, 1 367 30 40.2 -0.3369 355 0.000127 16103 50.25

histo_Past_20091009:TRIP 7845, 2 339 47 18.3 -0.3854 311 0.000227 10167 54.09

histo_Past_20091009:TRIP 7845, 3 291 49 32.6 -0.4262 275 0.000185 9304 53.92

histo_Past_20091010:TRIP 7845, 1 199 14 15.5 -0.1850 182 0.000219 6193 52.30

histo_Past_20091010:TRIP 7845, 2 225 27 15.4 -0.1822 210 0.000155 10044 52.13

histo_Past_20091012:TRIP 7845, 1 401 87 40.6 -0.2058 366 0.000189 4906 52.45

histo_Past_20091012:TRIP 7845, 2 283 64 12.5 -0.1966 254 0.000192 4426 44.45

histo_Past_20091012:TRIP 7845, 3 503 137 24.8 -0.1874 451 0.000261 5362 50.46

histo_Past_20091012:TRIP 7845, 4 206 25 30.9 -0.1762 191 0.000150 2758 47.72

histo_Past_20091012:TRIP 7845, 5 447 112 76.3 -0.1687 367 0.000141 6665 48.19

histo_Past_20091013:TRIP 7845, 1 73 0 3.4 -0.2343 63 0.000429 814 0.00

histo_Past_20091013:TRIP 7845, 2 12 0 0.5 -0.2533 10 0.000538 351 0.00

Nb data % µsec nb Sigm Enrg Incidence

GPHYS, Obs. de Paris - 23 juin 2010 29

Campaign of time transfer : Paris - Grasse -Herstmonceux(UK), Borowiecz (Pol) and Koganei (J)

October 2009

&

June-Sept 2010

GPHYS, Obs. de Paris - 23 juin 2010 30

Campaign Obs. Paris, Grasse, Borowiecz & Koganei

GPHYS, Obs. de Paris - 23 juin 2010 31

DORIS USO