0 - Technical description of solution aus2018a.cat 1 - Technique: VLBI 2 - Analysis Centre: Geoscience Australia 3 - Software used: OCCAM 6.3 4 - Data span: January, 1980 - 27 March, 2018 9,433,411 group delays Weighted rms is 20.0 pks 5 - Celestial Reference Frame: ICRF2 a - Nature: extragalactic b - Definition of the orientation: ICRF2 6 - Terrestrial Reference Frame: itrf2008 and associated itrf2008 velocity field a - Relativity scale: Solar System Bary Center (SSB) b - Velocity of light: 299792458 m/s c - Geogravitational constant: not applicable d - Permanent tidal correction: no e - Definition of the origin: NNT constraints on the daily basis for all VLBI stations, except Tigoconc, Yarra12M, Kath12M, Ishioka, Kunming, WETTZ13N, Metsahov, DSS65A, Parkes and Tsukub32, after the 2011 earthquake f - Definition of the orientation: NNR constraints on the daily basis for all VLBI stations, except Tigoconc, Yarra12M, Kath12M, Ishioka, Kunming, WETTZ13N, Metsahov, DSS65A, Parkes and Tsukub32 after the 2011 earthquake g - Reference epoch: 2005.0 h - Tectonic plate model: itrf2008 velocities used as apriori; exponential model for Gilcreek after the Denali, 2002 earthquake [Titov, Tregoning; 2004] i - Constraints for time evolution: None 7 - Earth orientation: a - A priori precession model: IERS 2003 b - A priori nutation model: MHB2000 c - Short-period tidal variations in x, y, UT1: Model used according to: R.Eanes (2000) as in IERS Conventions 2000 8 - Estimated Parameters: a - Celestial Frame: - right ascension and declination of 4267 sources with two and more observations (group delays) as global parameters; LOOSE (!) NNR constraint (1.d6) was imposed on 295 ICRF2 defining sources during each session. - all sources are estimated as global parameters b - Terrestrial Frame: Daily x, y, z values for all sites with further estimation of (x0,y0,z0) referred to 2005.0 and corresponding velocities c - Earth Orientation: xp, yp, UT1-UTC, dpsi, deps d - Others: - clock offsets, rates and 2nd derivatives; - wet zenith tropospheric delays; Clock offsets, wet delays and EOP were considered as stochastic parameters with relevant covariance functions. VMF1 mapping function [Boehm, Schuh; 2004] has been applied for the troposphere modeling - wet troposphere gradients were estimated as daily parameters for comparison - Downweighting procedure: The observations below elevation of 15 degrees were downweighted, but without addition of the extra noise in quadrature as it is done in CALC/SOLVE. References: Boehm J., H.Schuh, Vienna Mapping functions in VLBI analysis, Geoph. Res. Lett., 31 L01603 DOI10.129/2003GL018984, 2004. Eanes R., private communication, 2000. Ma, C., et al., The International Celestial Reference Frame as realized by Very Long Baseline Interferometry, AJ, 116, 516-546, 1998. Titov O., P. Tregoning, Post-Seismic Motion of Gilcreek Geodetic Sites Following the November, 2002 Denali Earthquake, in International VLBI Service for Geodesy and Astrometry 2004 General Meeting Proceedings, edited by Nancy R. Vandenberg and Karen D. Baver, NASA/CP-2004-212255, 2004.