Study of RAIM algorithms for combined GPS/Galileo receivers

Abstract

Integrity of a GNSS (Global Navigation Satellite System) is one of the most important performance parameter for safety applications like air navigation. For Oceanic, En route or Non Precision Approach (NPA) phases, the integrity requirements as defined by the ICAO (International Civil Aviation Organisation) should be fulfilled by the future Galileo Safety of Life Service. 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. The aim of this work is to investigate the RAIM performances that can be expected using a combined Galileo/GPS navigation system for a defined scenario, and to compare these results with requirements.