A New Relative Receiver Autonomous Integrity Monitoring Algorithm for Multiple Failures

Abstract

In near future, GNSS GPS modernization, renewed GLONASS and a new Galileo signal will be available. And the accuracy of position solution will be better by courtesy of improved quality of ranging signal. As an expected accuracy is better, the threshold for failure will be reduced. As a result, the prior probability of failures could be larger than what is used now. Due to the increased prior probability of failures, probability of simultaneous multiple failures cannot be neglected any more. Furthermore there will be many more ranging sources makes it necessary to consider the possibility of simultaneous multiple failures. This paper develops and analyzes a new Relative Receiver Autonomous Integrity Monitoring (RRAIM) algorithm which can treat no only a single failure but also simultaneous multiple failures. A proposed algorithm uses measurement residuals and satellite observation matrices of several consecutive epochs for Failure Detection and Exclusion (FDE). It detects failures by monitoring the error vector itself instead of monitoring the projection of the error vector. The simulation results show that the algorithm is able to detect any instance of multiple failures which are not detected by the conventional RAIM algorithm.