Processing Combined GPS/GLONASS Data at swisstopo s Local Analysis Center

Transcription

1 armasuisse Federal Office of Topography swisstopo Processing Combined GPS/GLONASS Data at swisstopo s Local Analysis Center D. Ineichen, E. Brockmann, S. Schaer

2 GLONASS data used for EUREF solutions swisstopo s official contribution based on GLONASS data since GPS week 1400 (Nov. 2006) Increase from 4 to 8 GNSS stations in swisstopo ss sub- network compared to last year New Swiss EUREF site ZIM2 providing GNSS data GLONASS ambiguity fixing implemented since August 2007 Orbit information used from CODE (no combined product available from IGS) ZIM2 WTZR UNTR 2

3 Current GNSS status of the AGNES network Normal station : GNSS receiver and antenna installed Double station : New antenna mount for GNSS antenna GNSS and GPS run simultaneously Double station : GNSS not yet installed New equipment: Trimble NetR5 receivers and Zephyr GNSS antennas 3

4 Reference frame stability: Coordinate jumps due to antenna change The change to GNSS capable Station Luzern (antenna change July 11, 2007) antennas caused jumps in the coordinate time series 4

5 Reference frame stability: New coordinates for AGNES reference sites Difference [m mm] Difference between new and old official coordinate values North East Up -30 AN NDE EP PFL FA ALE FH HBB GE ENE HA ABG HU UTT KR REU LO OMO LU UZE NE EUC PA AYE SA AME SA ANB SA ARG SC CHA ST TCX ST TGA UZ ZNA ZE ERM Total difference is the sum of antenna change, station movement since last determination, and rounding effects of the old coordinates Double stations help to ensure the consistency of the national reference frame during transition time 5

6 Post-processed daily solutions of the AGNES network Evaluate the performance of different solution types, amongst others: GPS only solution GLONASS only solution GNSS solution (combined on NEQ level) with individual (GPS) antenna calibration values Time series of 23 GNSS observation sites Covered time period of 315 days (July 07 to May 08) Data processing with Bernese GNSS Software

7 Post-processing of the AGNES network: GPS+GLONASS GLONASS solution GPS+GLONASS solution: Station ETH2, 300 Days GNSS only solution: Station ETH2, 300 Days 7

8 Post-processing of the AGNES network: GPS only solution GPS only solution: Station ETH2, 300 Days 8

9 Post-processing of the AGNES network: GLONASS only solution GLONASS only solution: Station ETH2, 300 Days 9

10 Post-processing of the AGNES network: Repeatability of the North component 4 3 GPS only GPS+GLONASS GLONASS only RMS [mm] ANDE ARD2 DAV2 EPFL ETH2 FALE FHBB GENE HOH2 HUTT KALT KREU NEUC PAYE SAME SANB SARG SCHA STA2 STCX STGA ZERM ZIM2 10

11 Post-processing of the AGNES network: Summary of the repeatability values Mean RMS of 23 Stations, ti 315 days 6 5 GPS only GPS + GLONASS GLONASS only 4 m] RMS [m North East Up 11

12 Post-processing of the AGNES network: Coordinate consistency between the solutions RMS of Helmert Transformations (3 translation parameters): North [mm] East [mm] Up [mm] GPS vs. GNSS GLONASS vs. GNSS GPS vs. GLONASS

13 Kinematic solutions: Approach Data processing in hourly batches (for 7 days) Ambiguities and troposphere parameters introduced from a post-processed d8h 8-hour-solution Estimation of epoch-wise coordinates (every 30 seconds) for all AGNES sites, fixing i European sites Comparison of a GPS only solution with a GNSS solution Simulating the measuring in kinematic positioning mode 13

14 Kinematic solutions: Residuals of GPS vs. GNSS solutions Station San Bernardino, 7 days, position estimates North East 14

15 Kinematic solutions: Influence of GNSS on RMS values GPS only GNSS RMS North, DOY 155, 2008 [mm] ANDE ARD2 DAV2 EPFL ETH2 FALE FHBB GENE HOH2 HUTT T KALT KREU LUZE MAR2 NEUC PAYE SAME SANB SARG SCHA STCX STGA ZERM ZIM2 Improvement for all sites in all components when using additional GLONASS observations 15

16 Kinematic solutions: Improvement using additional GLONASS data Mean values of 7 days, 24 stations: North East Up RMS GPS 7.3 mm 5.4 mm 12.4 mm RMS GNSS mm mm 10.8 mm Improvement 17 % 11 % 13 % Gain up to 30% for North, 13% for East, and 16% for Height component for stations in mountainous regions 16

17 Influence of GLONASS on the estimation of tropospheric parameters Comparison of the Zenith Total Delays, Station ETH2, December 23 to 30,

18 Conclusions AGNES network almost completely re-equipped with GNSS receivers/antenna during last year GNSS data is routinely processed for EUREF, AGNES, and near-realtime realtime solutions On daily level, the GPS and GNSS solutions are almost on the same level, l although h the GLONASS only solution performs remarkably well In kinematic mode, additional GLONASS data help to improve the coordinate estimates 18