An Improved Weight Optimization AAIM Method Aided by Barometric Altimeter

Abstract

Aiming at the problem of insufficient availability in the satellite receiver autonomous integrity monitoring (RAIM) method, an improved aircraft autonomous integrity monitoring (AAIM) method aided by barometric altimeter based on weight optimization is proposed under the actual configuration of the airborne navigation system. The information of satellite navigation system and barometric altimeter is used to establish the observation equation of the integrated system. The algorithm for integrity monitoring and protection-level calculation is derived based on multiple solution separation, and a weight optimization is adopted to achieve a trade-off between position accuracy and integrity, which can improve the availability of AAIM method. The simulation experiment shows that when the number of visible stars is 5, the traditional method cannot effectively detect the satellite fault, and the positioning error is 43.65 m. The improved algorithm can effectively isolate the fault and reduce the positioning error to 0.37 m. Compared with the traditional RAIM algorithm and the Baro-aided AAIM algorithm, the proposed algorithm has a lower vertical protection threshold. Therefore, the algorithm in this paper improves the performance of satellite navigation system integrity monitoring and ensure the accuracy and reliability of the satellite navigation system.