Impact of SLR long-term mean range biases on the orbits of altimetry and SLR satellites for ITRS2020 realizations

In 2022-2023, new (2020) realizations of the International Terrestrial Reference System (ITRS) were published, namely ITRF2020, DTRF2020, and JTRF2020. One of the differences for these realizations with respect to the previous (2014) ones is the application of Satellite Laser Ranging (SLR) station-specific long-term mean range biases for the four geodetic satellites LAGEOS-1, -2 and Etalon-1 and -2. These range biases were subtracted at the observation level from the SLR observations used to derive the ITRS2020 realizations. In this context, a question arises if these range biases should be applied in SLR-observation-based precise orbit determination for any satellite to obtain the highest orbit quality possible, when using ITRS2020 realizations as the a priori reference frame. We present results of a study on the application of the SLR long-term mean range biases derived from LAGEOS-1, -2 and Etalon-1 and -2 for precise orbit determination of some altimetry and other spherical SLR satellites using ITRS2020 realizations as the a priori reference frame and make a conclusion on the necessity of application of these biases. Furthermore, we present results of precise orbit determination for altimetry satellites based on long-term mean range biases explicitly determined for the respective satellites.