Extended Receiver Autonomous Integrity Monitoring (eRAIM) for GNSS/INS Integration

The integration of globe navigation satellite system (GNSS) with inertial navigation system (INS) is being heavily investigated as it can deliver more robust and reliable systems than either of the individual systems. In order to ensure the integrity of navigation solutions, it is necessary to incorporate an effective quality control scheme which uses redundant information provided by both the measurement and dynamic models. As the GNSS receiver autonomous integrity monitoring (RAIM) algorithms are well developed, here they are adapted to integrated GNSS/INS systems referred as extended RAIM (eRAIM), which are derived from the least-squares estimators of the state parameters in a Kalman filter, to assess GNSS/INS performance for a tightly coupled scenario. In addition to the RAIM capabilities, eRAIM procedures are able to detect faults in the dynamic model and isolate them from the measurement model. The analysis includes outlier detection and identification capabilities, reliability and separability measures of integrated GNSS/INS systems. The performance of the system is also investigated with respect to diminishing satellite visibility conditions.