Sub-Decimeter Onboard Orbit Determination of LEO Satellites Using SSR Corrections: A Galileo-Based Case Study for the Sentinel-6A Satellite

In GNSS-based navigation onboard Low Earth Orbit (LEO) satellites, typical accuracy requirements are 10 cm and 0.1 mm/s for 3D position velocity, respectively. Previous works have shown that such performance is achieved by including Galileo measurements in the estimation process. Here, we aim to evaluate impact of employing State Space Representation (SSR) corrections, i.e., GNSS satellite orbit, clock, biases, be applied broadcast ephemerides. this framework, Precise Onboard Determination (P2OD) software (SW) tool developed at University Padua (UNIPD) used investigate needs navigation. The UNIPD SW employs an Extended Kalman Filter (EKF) using a reduced-dynamics approach. force model implemented adapted processing, empirical accelerations included take into account residual mismodeling. Actual observation data from LEO Sentinel-6A processed along with SSR corrections CNES service. Galileo-based solutions compared ground-based POD reference orbits. analysis suggests use provides sub-decimeter below accuracies Such results indicate P2OD solution quality close achievable adopting precise orbits clocks.