Impact of new models for the ITRF2020 in VLBI analysis at DGFI-TUM

Abstract:

Within the next years, the ITRS Center of the International Earth Rotation and Reference Systems Service (IERS) is going to generate the new realization of the International Terrestrial Reference System, the ITRF2020. The reprocessing of the input data has to be performed with a variety of new geophysical and technical models, which are either relevant for all or a subset of the geodetic space techniques. With respect to the contribution of Very Long Baseline Interferometry (VLBI), the Analysis Centers (ACs) of the International VLBI Service for Geodesy and Astrometry (IVS) are obliged to include four new models in their submissions: the secular pole function as agreed upon at the Unified Analysis Workshop (UAW) 2017, the Desai and Sibois [2016] model for sub-daily EOP variation due to ocean tides, the latest realization of the International Celestial Reference System (ICRF3, including Galactic Aberration), and an empirical model for the gravitational deformation of selected VLBI antennas. While multiple studies have been conducted to validate the distinct models, the impact of their combined application in VLBI analysis has not been fully investigated yet. In this presentation, we will describe the new VLBI solutions obtained at DGFI-TUM with our DGFI Orbit and Geodetic parameter estimation Software (DOGS). Thereby, the four models are introduced successively, so as to distinguish their individual contributions and to identify their impact on the various types of estimated parameters.