CoAuthors

Florian Reckeweg (ESA/ESOC, Germany); Michiel Otten (ESA/ESOC, Germany); Tim Springer (ESA/ESOC, Germany); Volker Mayer (ESA/ESOC, Germany); Erik Schoenemann (ESA/ESOC, Germany); Rene' Zandbergen (ESA/ESOC, Germany); Werner Enderle (ESA/ESOC, Germany)

With global mean sea level rising because of climate change, Copernicus Sentinel-6 is the radar altimetry reference mission to extend the legacy of sea-surface height measurements until at least 2030. The satellite carries a Poseidon-4 radar altimeter and a microwave radiometer. The analysis of the altimeter data relies on highly-accurate knowledge of the orbital position, in particular in the radial component, with errors below 1.5 cm. For this reason, Sentinel-6 carries several instruments, e.g. Laser Retroreflector Array, Doppler Orbitography and Radiopositioning Integrated By Satellite (DORIS) and also a GNSS receiver for generation of data, which allows to perform Precise Orbit Determination (POD) with the highest possible accuracy. Of particular interest for this paper is the GNSS receiver, because it is the first time that a high quality dual frequency Galileo/GPS receiver is flown on-board of a Sentinel satellite.

ESA’s Navigation Support Office (NavSO), located at the European Space Operations Centre in Darmstadt, Germany is providing an independent Precise Orbit Determination solution for all Sentinel satellites. As part of this activity, the office has been operationally computing and delivering the POD products, including the Sentine-6 multi-GNSS-based precise orbits since its launch in November 2020.
This presentation will describe the processing techniques adopted at the European Space Agency, with a particular focus on the POD aspects and the related processing of the Galileo and GPS observations. The latest results and their validation will be addressed in this context.