ARAIM Using GPS, GLONASS and BeiDou

Abstract

An Advanced Receiver Autonomous Integrity Monitoring (ARAIM) approach is applied using observations from the three GNSS systems GPS, GLONASS and BeiDou. Emphasis in this multi-constellation GNSS ARAIM is on meeting requirements of the Localizer Performance with Vertical guidance at 200 feet (LPV-200) for aircraft precision approach down to 200 feet (61 metres). The inclusion of the three systems in ARAIM was first discussed. The fault modes and probabilities using the combined system are next presented followed by a description of the used processing and testing strategy. Validation of the method is performed using real data collected over two days at five Multi-GNSS Experiment (MGEX) sites of a global distribution. The performance of the combined constellations is compared with the case when using only GPS. Results show that supplementing GPS with GLONASS+BeiDou observations, despite the decreased preliminary confidence placed in them compared with GPS, results in a substantial improvement to ARAIM availability. The improvement in the vertical position error (VPE) of the combined system was limited; however, the VPE values were in general constrained within ±3 m and were mostly bounded within the vertical protection level (VPL), indicating an improved autonomous integrity performance.