WEGENER Nice 2006 OLG Monitoring of the Eastern Mediterranean and Arabia Velocitiy Estimations of Permanent GPS Stations 1Space Research Institute, Austrian.

WEGENER Nice 2006

OLG Monitoring of the Eastern Mediterranean and Arabia

Velocitiy Estimations of Permanent GPS Stations

1 Space Research Institute, Austrian Academy of Sciences2 Federal Office of Metrology and Surveying (BEV)

Cornelia Haslinger1, Günter Stangl2

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MON Mediterranean Oriental Network

50 Stations

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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

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MON StationLateral Velocities

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MON StationVertical Velocities

AMMN, NAMA, SOLA

Probably computational artefacts or local effects

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Time Series New IGD1/NOA1

• IGD1 (Athens) velocities similar to DION (Dionysos) • NOA1 (Athens) still too young

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Time Series New AUT1

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Changing Velocity

• MIT pre-earthquake velocity (1998/9)• OLG velocity after – difference 5 mm/year

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Time Series Problems (1)

• Gap by missing data - jump at restart ?

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Time Series Problems (2)

• Large up velocity, but time series ok

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Time Series Seasonal Effects (1)

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Time Series Seasonal Effects (2)

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Time Series Seasonal Effects (3)

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Time Series Seasonal Effects – Model Effect?

BSW 5.0 Niell Dry+Wet

Tropospheric gradientsBSW 4.2 Dry Niell

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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

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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

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Thank You !