CoAuthors

Denise Dettmering (DGFI-TUM, Germany); Mathis Bloßfeld (DGFI-TUM, Germany); Julian Zeitlhöfler (DGFI-TUM, Germany); Riva Alkahal (DGFI-TUM, Germany)

Precise orbits of altimetry satellites are a basis for sea surface height estimation, since they provide the reference for the measured distance from a satellite altimeter to a water surface. Various factors affect accuracy of orbits of these satellites, such as type and quality of observations used, proper corrections of measurements, proper modelling of satellite shape, size, optical properties of its surfaces and its orientation in space, accurate modelling of forces acting on a satellite, accurate terrestrial and celestial reference frame realizations and transformation between them, proper modelling of displacements of tracking stations, a proper parameter adjustment algorithm, observation weighting and other factors. Significant progress has been reached in precise orbit determination of altimetry satellites in the latest decades by different orbit determination groups. In this presentation, we investigate the accuracy in the radial direction of contemporary orbits of such altimetry satellites as TOPEX/Poseidon, Jason-1, Jason-2, Jason-3, Sentinel-3A and some others derived in the ITRF2014 realization by various institutions using various types of observations covering totally time span from 1992 until 2021. We investigate single-satellite altimetry crossover differences, radial errors of individual orbit solutions and orbit differences in the radial direction between various orbit solutions for each satellite.