Method of Inertial Aided Satellite Navigation and Its Integrity Monitoring

A new tightly coupled integrated system of Global Navigation Satellite System(GNSS) aided by Strapdown Inertial Navigation System(SINS) and its integrity monitoring method is proposed in this paper for avoiding the disadvantage of conventional method in which all the observations are influenced by SINS and the fault can not be isolated.The tightly coupled integrated architecture and the Kalman filer are designed,in which the SINS measurements are conversed to virtual pseudorange and used as an extend to GNSS measurements.A Residual Chi-square Test Method(RCTM) and an Autonomous Integrity monitoring by Extrapolation Method(AIME) are presented to detect fault based on the innovation of Kalman filer.The GDOP can be reduced by choosing a virtual satellite based on the method,and the integrated architecture is favorable for integrity monitoring.The simulation results show that navigation accuracy can be improved effectively,and the RCTM can detect both step failure and quickly growing failure effectively,while for slowly growing failure the AIME algorithm has better performance.