Receiver autonomous integrity monitoring (RAIM) performances of combined GPS/BeiDou/QZSS in urban canyon

Multi-GNSS (global navigation satellite system) has become a trend to solve the urban canyon effect in order to meet the requirements of GNSS users, but the probability of mistaken satellites is also increasing with the increase in the number of visible satellites. The receiver autonomous integrity monitoring (RAIM) performance has therefore become very important. In this paper, the minimum RAIM availability (MRA) is proposed to evaluate the RAIM availability of combined GNSS constellations, and the minimal detectable effect (MDE) is applied to assess the RAIM fault detection capability. The significant improvements of RAIM performances in urban canyons when GPS/QZSS (quasi-zenith satellite system) are combined without and with BeiDou are quantified and analyzed by the simulations of the Asia-Pacific region snapshot and temporal variations in Beijing, Tokyo, Shanghai, and Hong Kong with different masking angles. The combining of BeiDou with GPS/QZSS has great realistic significance, especially in the Asia-Pacific region. The evaluation measure of RAIM performances can be used to predict the availability of GNSS constellations under different conditions, and it can be also used to assess the availability and integrity of combined constellations. (c) 2014 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.