The TU Graz contribution to the International Terrestrial Reference Frame (ITRF 2020): Processing of 27 years of GNSS data

A global geodetic reference frame (GGRF), such as the International Terrestrial Reference Frame (ITRF), is fundamental for quantifying geophysical changes in the Earth system. Global navigation satellite systems (GNSS) are one of the four space-geodetic techniques contributing to the construction of the ITRF. In support of the ITRF2020 release, the International GNSS Service (IGS) conducted its third reprocessing campaign (repro3), covering the years 1994 to 2020. Graz University of Technology (TUG) participated for the first time as an analysis centre in such a reprocessing campaign and TUG has been acknowledged globally for its high quality GNSS products. In this article we want to present the approach of TUG for the repro3 campaign as well as present research and analysis showing the high quality of the TUG products.