Interference Mitigation and T-RAIM for Robust GNSS Timing

Several layers of defense exist to improve Global Navigation Satellite System (GNSS) receiver performance in the presence of interference. These defenses are implemented at different receiver stages and include pre-correlation interference mitigation, post-correlation measurement screening and Fault Detection and Exclusion (FDE) at the Position, Velocity, and Time (PVT) level. This paper investigates the performance and interaction of these receiver defenses with specific focus on Robust Interference Mitigation (RIM) and Receiver Autonomous Integrity Monitoring (RAIM). The case of timing receivers with a known user position and Time-Receiver Autonomous Integrity Monitoring (T-RAIM) is also analysed. From the experimental analysis it emerges that RIM improves the quality of the measurements reducing the number of exclusions performed by RAIM. When timing solutions are considered, a more redundant measurement set is available and more exclusions are performed by T-RAIM, which is able to enhance solution reliability without compromising its availability.