François DIDELOT (CNES, FRANCE); Olivier DUMOND (CNES, FRANCE)

Sentinel-6b was launched on November 17, 2025. It is equipped with a DGXX-S generation DORIS receiver running the DIODE real-time navigation software. The mission is still in the calibration phase, but onboard navigation performance is already very good (~2.5 cm on the radial component compared to the precise orbits of CNES (POE)). The tandem phase with Sentinel-6MF—it is 30 seconds ahead of the latter—allows observation of the same DORIS beacons simultaneously on both missions and comparison of estimates of various local (tropospheric bias, clock bias) or global phenomena (atmospheric drag, Earth's rotation pole). These comparisons have shown that it is possible to optimize the DIODE navigator settings for Sentinel-6B but also for Sentinel-6MF, thus improving real-time positioning performance. These optimizations will be proposed to both projects for onboard upload in the near future. We propose to present these initial results here.

Keywords: DORIS, DIODE, Sentinel-6B