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OLG Monitoring of the Eastern Mediterranean and Arabia Velocitiy Estimations of Permanent GPS Stations. Cornelia Haslinger 1 , Günter Stangl 2. 1 Space Research Institute, Austrian Academy of Sciences 2 Federal Office of Metrology and Surveying (BEV). MON Mediterranean Oriental Network.
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OLG Monitoring of the Eastern Mediterranean and ArabiaVelocitiy Estimations of Permanent GPS Stations Cornelia Haslinger1, Günter Stangl2 1 Space Research Institute, Austrian Academy of Sciences 2 Federal Office of Metrology and Surveying (BEV) WEGENER Nice 2006
MON Mediterranean Oriental Network 50 Stations WEGENER Nice 2006
Processing • Weekly results (EPN standards, Bernese Software 4.2 +5.0) since 2000, extended to Indian Ocean 2000/1 and 2006 • Reference Minimum constraint solution on BUCU, GRAZ, SOFI with IGS/EPN ITRF2000 coordinates and velocities • EPN offsets for IGS/EPN stations applied • Raw time series checked for outliers (isolated values lateral >10 mm, vertical >20 mm) • Outliers removed cleaned time series • 50 Station velocities estimated (9 too short), BSW formal sigmas 0.1 mm/year • ITRF2000 rotation of Eurasia (Altamimi, Boucher 2002) removed -> velocities relative to Eurasia • Comparison to values of EPN, MIT (Reilinger et al. 2006), SOPAC WEGENER Nice 2006
MON StationLateral Velocities WEGENER Nice 2006
MON StationVertical Velocities AMMN, NAMA, SOLA Probably computational artefacts or local effects WEGENER Nice 2006
Time Series New IGD1/NOA1 • IGD1 (Athens) velocities similar to DION (Dionysos) • NOA1 (Athens) still too young WEGENER Nice 2006
Time Series New AUT1 WEGENER Nice 2006
Changing Velocity • MIT pre-earthquake velocity (1998/9) • OLG velocity after – difference 5 mm/year WEGENER Nice 2006
Time Series Problems (1) • Gap by missing data - jump at restart ? WEGENER Nice 2006
Time Series Problems (2) • Large up velocity, but time series ok WEGENER Nice 2006
Time Series Seasonal Effects (1) WEGENER Nice 2006
Time Series Seasonal Effects (2) WEGENER Nice 2006
Time Series Seasonal Effects (3) WEGENER Nice 2006
Time Series Seasonal Effects – Model Effect? BSW 5.0 Niell Dry+Wet Tropospheric gradients BSW 4.2 Dry Niell WEGENER Nice 2006
Comparison of Velocities • OLG time series <26 weeks excluded • OLG-EPN 14 stations <5 mm/year 5 stations 5-10 mm/year (ANKR, DRAG, RAMO, TRAB, all Up bias 7 mm/year, EPN problem) • OLG-MIT 24 stations <5 mm/year 4 stations 5-10 mm/year (MALI, POL2, SEY1, OLG problem, TUBI MIT problem) • OLG-SOPAC 17 stations <5 mm/year 5 stations 5-10 mm/year (IISC, KIT3, MALI, OLG problem, NSSP SIO problem, BAHR ?), 7 stations>10 mm/year (AMMN, DGAR, MALD, POL2, SEY1, OLG problem, HALY, TEHN SIO problem) • New stations (no comparison possible) AUT1, IGD1 WEGENER Nice 2006
Conclusions • Time series and 3D-velocity estimations of OLG cover a time span 2000-2006 • Permanent GPS stations in the Eastern Mediterranean monitored, most EPN corrections applied • IGS reference sites outside Europe included, but too short for reference->EPN referenced • Annual term in BSW 4.2 time series can be reduced by introducing a more refined model of the troposphere • Very good fit to GPS velocities of (Reilinger et al. 2006) • Reprocessing planned with ITRF2005 and absolute phase calibrations + improved model of the troposphere WEGENER Nice 2006
Thank You ! WEGENER Nice 2006