A No-Subset Method for ARAIM of Tightly-Coupled GNSS/INS to Reduce Computational Load

Advanced Receiver Autonomous Integrity Monitoring (Advanced RAIM, ARAIM) is the next generation of RAIM which is widely used in air transport. Based on tight integration of Global Navigation Satellite System (GNSS) and Inertial Navigation System (INS), the GNSS/INS ARALM attracts wide attention for its high performance with no additional cost. However, both of GNSS alone ARAIM and GNSS/INS ARAIM have to compute fault-tolerant position solutions of a large number of subsets, which results in a huge computational load. In this paper, a no-subset method for GNSS/INS ARAIM is proposed to conduct the fault detection test and to obtain the integrity and accuracy performances by computing a tight upper bound of the fault detection statistics and a tight bound of standard deviations of position errors, instead of the fault detection statistics and standard deviation of each subset. The computational load of the proposed algoritlun is about 1% of that of the current GNSS/INS ARAIM, which facilitates its application in the airborne navigation system. Moreover, the simulation results show that the integrity and accuracy performances of the proposed GNSS/INS ARAIM are able to meet the corresponding requirements of CAT-I with global coverage.