Sentinel-6A precise orbit determination using a combined GPS/Galileo receiver

Abstract The Sentinel-6 (or Jason-CS) altimetry mission provides a long-term extension of the Topex and Jason-1/2/3 missions for ocean surface topography monitoring. Analysis altimeter data relies on highly-accurate knowledge orbital position requires radial RMS orbit errors less than 1.5 cm. For precise determination (POD), Sentinel-6A spacecraft is equipped with dual-constellation GNSS receiver. We present results POD solutions first 6 months since launch demonstrate 1-cm consistency ambiguity-fixed GPS-only Galileo-only product. A similar performance (1.3 cm 3D RMS) achieved in comparison kinematic reduced-dynamic orbits. While Galileo measurements exhibit 30–50% smaller those GPS, benefits most from availability an increased number satellites combined dual-frequency solution. Considering obvious uncertainties pre-mission calibration receiver antenna, independent inflight phase centers GPS signal frequencies required. As such, observations cannot provide scale information estimated height ultimately driven by employed forces models center-of-mass location within spacecraft. Using satellite laser ranging (SLR) selected high-performance stations, better 1 SLR normal points GNSS-based orbits obtained, which further improves to mm when adjusting site-specific corrections station positions biases. component, bias found analysis relative mean 13 stations. Overall, based tracking considered readily meet altimetry-related needs