aus00007.eops.txt Technical description of solution aus00007 1. Purpose of solution: Session EOP 2. Analysis Center: GEOSCIENCE AUSTRALIA (AUS) 3. Short narrative description of solution: Observational VLBI time delays ( IRIS-A/NEOS-A) since 1983 have been analyzed for this solution. Reductional model is realised in accordance with the IERS Conventions (2000) except recommended precession/nutation model. IAU 1980 Nutation model is applied for correction. Celestial reference frame was fixed to the ICRF Ext.2 catalogue. Terrestrial reference frame was fixed by the VTRF2005 coordinates and velocities. All parameters under estimation have been adjusted using Kalman filter technique. New Vienna mapping function (VMF1) is applied for troposphere correction modeling. Tropospheric gradients have been considered as constant parameters. 4. Estimated parameters: a. celestial frame: No b. terrestrial frame: Yes c. Earth orientation: X, Y, UT1-UTC, X-dot, Y-dot, LOD, dpsi, deps d. zenith troposphere: Random walk process e. troposphere gradients: Estimates as a constant parameters f. station clocks: Offset as a random walk process, rate as a constant except sessions when the clock rate is considered as a random walk process for separate stations g. baseline clocks: No h. other: No 5. Celestial reference frame: a. a priori source positions: ICRF Ext.2 solution b. source positions adjusted in solution: No e. solution identification or reference: ICRF Ext.2 6 - Terrestrial reference frame: a. a priori station positions: VTRF2005 solution exception GILCREEK after 03-Nov-2002 b. a priori station velocities: VTRF2005 solution exception GILCREEK after 03-Nov-2002 c. reference epoch: 1997.0 d. station positions/velocities adjusted in solution: station positions are fixed to their VTRF2005 coordinates l. solution identification or reference: VTRF2005 7. Earth orientation: a. a priori precession model: IAU(1976) b. a priori nutation model: IAU(1980) c. a priori short-period tidal variations in x, y, UT1: IERS Conventions (2000) - model by R.Eanes d. EOP estimation: X, Y, UT1-UTC, dpsi, deps every session 8. A priori geophysical models: a. troposphere: Vienna mapping function (VMF1) for dry and wet delays b. solid Earth tide: IERS Conventions 2000, except re-instating for permanent tides. c. ocean loading: IERS Conventions 2000 d. atmosphere loading: applied for all VLBI sites 9. Data type: delays 10. Data editing: Only data with zero quality flag in NGS format are used 11. Data weighting: Kalman filter checks a quality of every observation and downweights it in case of bad result. 12. Standard errors reported: Formal errors are derived from Kalman filter adjustment 13 Software: OCCAM 6.2 14. Other information: Gilcreek after the seismic event 03-Nov-2002 has the following shift for apriori coordinates. Up = 0.8 mm North = -47.8 mm East = 22.6 mm Positions and velocities used for Australian and New Zealand stations as below TC HOBART12 -3949990.1702 2522421.0888 -4311708.6940 AZEL .00000 7240 TV HOBART12 -.0389 .0085 .0403 TC KATH12M -4147354.010 4581542.22 -1573303.93 AZEL .00000 7375 TV KATH12M -.0389 .0085 .0403 TC YARRA12M -2388895.801 5043349.334 -3078591.628 AZEL 0.00000 7238 TV YARRA12M -.0200 .0430 .0480 TC WARK12M -5115324.46 477843.25 -3767192.86 AZEL .00000 7377 TV WARK12M .0000 .0000 .0000 Moreover, exponential model has been applied for post-seismic effect approximation ---------------------------------------------------------------------- Dr. Oleg Titov Tel: +61-2-62499064 Research scientist Fax: +61-2-62499929 Geoscience Australia PO Box 378, Canberra, ACT, 2601, Australia e-mail: Oleg.Titov@ga.gov.au