Ramose RAIM: A multiple-failure detection algorithm design for civil aviation

With the advent of Galileo and Chinese Compass, GNSS navigation technologies will develop rapidly. However, as the number of navigation satellites in view will increase, the fault probability will rise. This paper calculates the multi-fault risk of multi-constellation satellite navigation system in terms of MOPS. It is highlighted that the probability of either one-fault or doublefaults is higher than integrity requirement. The paper also describes a snap-shot ramose RAIM technology to protect civil aviation users in multiple-fault case. In this condition, a series of FDE calculation is adopted to separate satellites in sight into several groups. Therefore the problem will transform into several single-fault case, which current RAIM can solve. Simulation results verify that this technique is proper to solve both single-fault and double-fault problem of civil aviation caused by application of multiconstellation GNSS.