DORIS data processing with Bernese GPS Software at GOPE: tests, initial results and future prospects

Transcription

1 DORIS data processing with Bernese GPS Software at GOPE: tests, initial results and future prospects Petr Štěpánek, GOPE, Czech rep. Urs Hugentobler, AIUB, Switzerland Karine Le Bail, IGN, France

2 DORIS in Bernese software CDDIS DATA FILES ORBITS DOROBS DORIS Simulated data Internal format Dynamical orbit GPSSIM GPSEST ORBGEN Internal format NEQ System Elements ADDNEQ

3 Measurement ρ (T) = km RANGE RATE V BEGINNING OF OBS. T COUNT INTERVAL T set-up of unknown Ambiguity A A ~ km -ρ(t) Measurement ρ(t+ T)= - TV+ km

4 Tests processing with fixed POE orbit (network estimation) processing with fixed network (orbit estimation) low constrained solution (network, EOP) used data: CDDIS, format., September 4

5 Data processing with fixed orbit CDDIS troposphere corrections or Estimated troposphere Mutual comparison of monthly mono-satellite solutions: Spots and Envisat - cm, Spot and Topex -3 cm. Higher differences in East component In the case of Estimated troposphere ( 3 cm, 5 cm in the case of Topex). Comparison with ITRF CDDIS tropo N.8 cm E. cm U,6 cm Estimated tropo N 3, cm E 3.4 cm U.3 cm Scale vs. ITRF: Topex -9 ppb, spots around -5 ppb, Envisat -3 ppb

6 Orbit estimation Fixed network Troposphere - CDDIS corrections X estimated Reduced dynamical (GPS) model No exact models for non-conservative forces 9 Empirical parameters (3 constant + 6 harmonic) Stochastic parameters (set per 5 min, constraints ~ -5 m/s) Topex, Jason - radial Spots, Envisat - radial, along track, out of plane

7 Comparison with POE Comparison of Estimated DORIS orbit and POE in radial component RMS (cm) TOPEX/CDDIS tropo SPOT-5/CDDIS tropo TOPEX/Estimated tropo SPOT-5/Estimated tropo

8 Low constrained solution 3 weekly solutions 5 satellites (except Jason) m network constraints, ITRF apriori comparison with corresponding IGN/JPL and LCA solutions Estimated: Network, Xpole, Ypole Preeliminated: Orbit, Beacon frq. offset, Troposphere ZTD

9 RMS (cm) Coordinates comparison with ITRF Latitude Longitude Height Topex Spot- Spot-4 Spot-5 Envisat Comb.

10 Scale vs. ITRF - Scale (ppb) Spot- Spot-4 Spot-5 Envisat Komb Topex

11 Translation (cm) Translation vs. ITRF Tx Ty Tz Topex Spot- Spot-4 Spot-5 Envisat Comb.

12 Comparison of the network estimation results with current IDS results Repeatability GOPE Repeatability (cm) 4 3 IGN LCA Latitude Longitude Height Coordinates comparison with ITRF Mutual comparison of coordinates 4 4 RMS (cm) 3 GOPE-ITRF IGN-ITRF LCA-ITRF Latitude Longitude Height RMS (cm) 3 GOPE-IGN GOPE-LCA IGN-LCA Latitude Longitude Height

13 Translations vs. ITRF Translation (cm) X- translation vs. ITRF GOPE/AIUB IGN LCA Translation (cm) - - Y- translation vs. ITRF GOPE/AIUB IGN LCA week I week II week III week I week II week III Z- translation vs. ITRF Translation (cm) GOPE/AIUB IGN LCA week I week II week III

14 5 4 A posteriori RMS of observations GOPE FIMBI RMS (mm) 3 Topex Spot- Spot-4 Spot-5 Envisat

15 Comparison of the pole estimation results with current IDS results Difference (mas) X-Pole comparison with IERS C4 GOPE IGN LCA Difference (mas) - - Y-Pole comparison with IERS C4 GOPE IGN LCA Days of September 4 Days of September 4

16 Outlook Several technical steps Semi-automatic data processing Processing of longer data time-series Routine data processing, weekly and/or monthly solutions. Orbit model improvement

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