CoAuthors

Claudia Flohrer (ESA/ESOC, Germany); Tim Springer (ESA/ESOC, Germany); Werner Enderle (ESA/ESOC, Germany)

In this presentation we will present the Sentinel-3A and Sentinel-3B orbits generated at the European Space Operation Centre (ESOC) as part of our Corpernicus activities. We will highlight the improvements that have been made in our software (NAPEOS) as well as in our satellite modelling since the last OSTST meeting. Data of all three tracking instruments on-board the satellites, i.e., GPS, DORIS, and SLR measurements, were used in a combined data analysis.

The main focus of this presentation will be on the integer ambiguity resolved orbits for both missions. In NAPEOS we are able to either resolve the integer ambiguities in a network approach in which the satellites are included in an IGS like setup or we can resolve the integer ambiguities using the GFZ/CNES method. The results of both these methods will be presented. Finally, we will address the effect of the close tandem phase on the possibility to perform combined orbit determination and the effect on the orbit determination of generating Sentinel-3A/B double differences.

We evaluate the orbit accuracy by analysing post-fit residuals, orbit overlap errors, and orbit differences between our orbits and external orbits generated by other analysis centres. The consistency between our solutions and external orbits is below the 1 cm level in the radial direction, the most crucial component for altimetry height measurements.