User Level Autonomous Integrity Monitoring for Seamless Positioning in All Conditions and Environments

This paper proposes a new GNSS user level integrity monitoring scheme for the detection and exclusion of simultaneous multiple failures. It addresses the weakness of the current methods that assume a single failure a time. The new approach, referred to as the “group separation method”, can be used either in the receiver autonomous integrity monitoring (RAIM) mode or its extension the user autonomous integrity monitoring (UAIM) when other sensors are used together with GNSS. The group separation method is based on multiple-effect analysis and identification of a common failure mode using prior-knowledge of GNSS and the user receiver measurements. The measurements are then grouped by potential common failure mode. The group most likely to fail has the highest priority for separation (exclusion). Simulation results using pseudorange measurements show that the group separation method is accurate and highly efficient.