Robust RAIM and FDI Schemes of GPS/UWB Positioning Receiver

Receiver Autonomous Integrity Monitoring (RAIM) of the Global Navigation Satellite System (GNSS) receiver is required for the safety-of-life navigation, such as the aviation and self-driving vehicles, which have a high demand for safety. In this situation, the RAIM is designed to provide the quality report of the navigation signal, allowing the navigation to continue without the interruption or jamming. The RAIM is conducted by using the redundancy of several ranging measurements from the multi-constellation navigation system, performing a voting mechanism to exclude the outliers and fault ranging measurements. The conventional RAIM algorithm for achieving the fault detection and isolation is carried out using the stand-alone GNSS. In this study, the signal of the opportunity from a ground positioning radio is further considered, such as fusing ground-based Ultra Wide Band (UWB) positioning measurements. In addition, an alternative RAIM with a Model Uncertainty (MU) is applied. In this manner, a higher performance and robustness can be obtained. To evaluate the performance, the probability of false detection is simulated; the fault detectability is investigated using the Minimal Detectable Bias (MDB) index. To verify, a GNSS/UWB positioning FPGA receiver was implemented with the RAIM.