Receiver Autonomous Integrity Monitoring for LEO Satellites: Outlier Detection and Exclusion

Robust Precise Orbit Determination (POD) is essential for Low Earth Orbit (LEO) satellite missions. Based on observational data from Global Navigation Satellite System (GNSS), the orbit parameters are estimated by means of an adjustment process. To achieve accurate results, highly reliable navigation data are required. In this work, we investigate the application of Receiver Autonomous Integrity Monitoring (RAIM)-based methods — originally developed for aviation — to detect and exclude faulty GNSS measurements in a post-processed POD framework. Our approach utilizes redundant GNSS code measurements and evaluates the residuals from a weighted least squares (WLSQ) orbit solution. Based on a predefined false alarm rate, we set a threshold and compare it to a residual-based test statistic. The method enables detection and exclusion of outliers in post-processed solutions. Simulation and real GRACE-FO data results demonstrate the effectiveness of the applied RAIM-based method. It enhances the integrity and reliability of GNSS-based POD solutions for LEO satellites.