Technical description of solution GAOUA 03 R 01 1 - Technique: VLBI 2 - Analysis Centre: Main Astronomical Observatory, National Academy of Sciences of Ukraine, Kiev, Ukraine 3 - Software used: SteelBreeze-2.0.2 4 - Data span: Aug 1979 -- Sep 2003 5 - Celestial Reference Frame: RSC(GAOUA)03 R 01 a - Nature: extragalactic b - Definition of the orientation: No Net Source Rotation of Position Constraints, [Gipson, 1998] were applied to 23 defining radiosources to tie their positions to initial coordinates of ICRF-Ext1 catalogue. 6 - Terrestrial Reference Frame: SSC(GAOUA)03 R 01 SSV(GAOUA)03 R 01 a - Relativity scale: SSB b - Velocity of light: 299792458 m/s c - Geogravitational constant: not applicable d - Permanent tidal correction: no e - Definition of the origin: No Net Translation Position Constraints [Gipson, 1998] were applied to 8 stations (ONSALA60, WETTZELL HARTRAO, ALGOPARK, KOKEE, WESTFORD, FORTLEZA and HOBART26) to tie their positions to initial coordinates of ITRF2000. f - Definition of the orientation: No Net Rotation of Position Constraints [Gipson, 1998] were applied to the same 8 stations. g - Reference epoch: 1997.0 h - Tectonic plate model: ITRF2000 velocity field was used instead of tectonic plate model i - Constraints for time evolution: No Net Translation Velocity and No Net Velocity Rotation [Gipson, 1998] were applied to the same 8 stations to tie their horizontal motions with the NNR-NUVEL-1A tectonic plate model. 7 - Earth orientation: EOP(GAOUA)03 R 01 a - A priori precession model: IAU 2000A Precession-Nutation Model b - A priori nutation model: IAU 2000A Precession-Nutation Model c - Short-period tidal variations in x, y, UT1: - Diurnal and semidiurnal tidal variations of model [Ray at al., 1994] as described in IERS Conventions 2003 (71 terms); - Polar motion induced by the non-tidal variations in oceanic angular momentum [de Viron, Goosse, Bizouard and Lambert]; - Diurnal and semidiurnal variations of polar motion due to atmospheric tides [Brzezinski, Bizouard and Petrov, 2002]. 8 - Estimated Parameters: a - Celestial Frame: right ascension and declination of all sources as global parameters b - Terrestrial Frame: X0, Y0, Z0 of all stations Xdot, Ydot, Zdot of stations with suitable for velocity determination history of observations c - Earth Orientation: x, y, UT1-UTC CIP coordinates in GCRS: dX and dY d - Others: - Clock parameters: a) polynomial coefficients b) stochastic component of clock behaviour - Wet zenith tropospheric delays as a stochastic parameter - Troposphere gradients as a stochastic parameters REFERENCES: Gipson, 1998: ftp://gemini.gsfc.nasa.gov/pub/misc/jmg/vlbifram.pdf Ray, R.D., Steinberg, D.J., Chao, B.F., and Cartwright, D.E., 1994, Diurnal and Semidiurnal Variations in the Earth's Rotation Rate Induced by Oceanic Tides, Science, 264, pp. 830--832. de Viron, Goosse, Bizouard and Lambert: http://hpiers.obspm.fr/eop-pc/models/PM/PM_oceanic_nt_hf_tab.html Brzezinski, Bizouard and Petrov, 2002, Influence of the atmosphere on Earth Rotation: what new can be learned from the recent atmospheric angular momentum estimates?, Surveys in Geophysics, 23, 33-69, 2002