A simulation study for future geodetic satellites tracked by satellite laser ranging

Abstract

Satellite laser ranging (SLR) measurements play a key role in determining global geodetic parameters, such as station coordinates, geocenter motion, low-degree Earth’s gravity field parameters, and Earth rotation parameters. Currently, the observations to the two LAser GEOdynamics Satellites (LAGEOS) and two Etalon satellites provide operational standard products and contribute to the realization of the scale and the origin of the International Terrestrial Reference Frame (ITRF). Nowadays under consideration is an extension of the ITRF realizations by including LAser RElativity Satellite (LARES). In July 2022, the LARES-2 satellite was launched with the main purpose to verify fundamental physics, especially the Lense-Thirring effect emerging from General Relativity. We simulate orbits and observations for the LARES-2 satellite, as well as the LARES-like satellites, which complement the current constellation of LAGEOS-1/-2 and LARES-1/-2 using the butterfly configuration. We assess the impact of the observations to satellites with different orbital parameters on the determination of global geodetic parameters. We show that placing a satellite in a retrograde orbit – orbiting against the Earth’s rotation at a high altitude of 5600 km, can substantially improve the quality of the global geodetic parameters. The LAGEOS-1/-2 + LARES-1/-2/-4 solution achieves the 3D mean error at the level of 1.62 mm for the station coordinates, and mean errors of 0.7, 0.7, and 1.3 mm for the X, Y, and Z geocenter components, respectively, bringing us closer to fulfilling the requirements established by the Global Geodetic Observations System (GGOS) of 1 mm accuracy for the reference frame stability.