ESA combined processing for Genesis

The Navigation Support Office (NSO) at the European Space Agency’s (ESA) European Space Operations Centre (ESOC) is producing precise navigation products utilising all space geodetic observation types. As of today, NSO generates and contributes to the global geodetic supply chain with individual solutions for Global Navigation Satellite System (GNSS) constellations, Satellite Laser Ranging (SLR), Doppler Orbitography and Radiopositioning Integrated by Satellite (DORIS), and Very Long Baseline Interferometry (VLBI). Previous studies demonstrated the performance improvement achieved by the Combination On the Observation Level (COOL) in the orbit determination system through the inclusion of Low Earth Orbiting (LEO) satellites and additional observation types in the GNSS processing. This integration at the observation level significantly strengthens the global parameter estimation. At the same time this combination makes more evident technique specific inconsistencies (e.g., inaccurate phase centers, station biases, model deficiencies) and enables further improvements. To further improve its precise navigation capabilities and to better support
the Global Geodetic Observing System (GGOS) goals as well as the upcoming Genesis mission, the Navigation Support Office is reviewing its processing setup, which is based on the state-of-the-art ESA Precise Navigation System (EPNS). The target is to exploit the full advantages of combining all available space observations on observation level. A pivotal first step in this effort is the integration of LEO satellites in the GNSS processing in conjunction with the inclusion of SLR observations to
GNSS and to the LEO. Further observations and techniques will be added step by step, carefully analysing their impact on and benefits for the COOL solution. Exploiting its newly developed GNSS processing system CHAMP, NSO take advantage of this combined processing to identify and quantify the effects of the multi-technique, multi-satellite co-processing on all constellations and satellites products, and the other parameters, such as Earth Orientation Parameters. This presentation outlines the NSO roadmap and presents the latest analysis of the Combination On the Observation Level, considering at least GNSS and SLR in different constellations.