Study of sequential RAIM algorithms for GPS receivers

Abstract

As for the International Civil Aviation Organisation (ICAO), the Global Navigation Satellite System (GNSS) shall have a sufficient performing system for positioning and navigation, so that it could be used as the Inertial Navigation System (INS) and why not replace it. Integrity of GNSS is one of the most important performance parameter for safety applications. One of the techniques that provide integrity check at receiver level is the so called Receiver Autonomous Integrity Monitoring (RAIM), which uses an over-determined navigation solution in order to make a consistency check. For that technique, numerous RAIM algorithms are available which have each advantages and drawbacks depending on the specific use. For instance, on the one hand, the snapshot algorithms are a memory less technique which manages to detect and exclude at each epoch faulty satellites. On the other hand, the sequential algorithms are techniques with memory making fault detection and exclusion taking in account previous observations. The aim of this work is to investigate the RAIM performances on the sequential technique that can be expected using a GPS navigation system for a defined scenario, and to compare these results with requirements and snapshot algorithms. Finally, this technique should be integrated in the EVNet of the DLR.