Analysis of GNSS Observations (GPS Weeks 1934–2105) for the Propagation of the IGS14 Reference Frame on the Territory of Ukraine

From January 29, 2017 to May 16, 2020 (GPS weeks 1934–2105) all products of the International GNSS Service (IGS)–precise ephemerides of GPS and GLONASS satellites, coordinates and velocities of permanent GNSS stations, etc.–were based on the IGS14 reference frame, the first IGS realization of the release of the International Terrestrial Reference Frame ITRF2014. Observations of GNSS satellites at permanent stations located in Ukraine and in the Eastern Europe for this period were processed in the GNSS Data Analysis Centre of the Main Astronomical Observatory NAS of Ukraine (MAO). The processing was carried out with the Bernese GNSS Software ver. 5.2 according to the requirements of the EUREF Permanent GNSS Network (EPN), that were relevant at that time. In total, observations on 277 GNSS stations, including 205 Ukrainian stations belonging to the following operators of GNSS networks: MAO NAS of Ukraine, StateGeoCadastre of Ukraine (UPN GNSS), NU Lviv Polytechnic (GeoTerrace), PJSC System Solutions (System.NET), TNT TPI company (TNT TPI GNSS Network), Navigation and Geodetic Center (NGC.net), UA-EUPOS/ZAKPOS, E.P.S. LLC, Coordinate navigation maintenance system of Ukraine (NET.Spacecenter), Kiev Institute of Land Relations (KyivPOS), KMC LLC, were processed. The IGS14 reference frame was realized by applying No-Net-Translation conditions on the coordinates of the EPN Class A stations from the EPN C2100 catalogue. As result, the stations’ coordinates in the IGS14 reference frame and the zenith tropospheric delays for all stations were estimated. The mean repeatabilities for components of GNSS stations’ coordinates for all weeks (the characteristics of the precision of the obtained daily and weekly solutions) are in the following ranges: for the northern and eastern components – from 0.6 to 1.4 mm (average values are 0.93 and 1.00 mm respectively) with outliers for the eastern component of 2.02 and 1.55 mm for GPS weeks 2085 and 2091 respectively, for height component – from 2.0 to 5.5 mm (average value is 3.51 mm).