Research on RAIM Algorithm Based on GPS/BDS Integrated Navigation

Abstract

In multi-constellation integrated navigation system, the multiplication of visible satellites makes the receiver autonomous integrity algorithm (RAIM) applied in approach flight phase of civil aviation become possible. For the GPS/BDS integrated navigation RAIM algorithm applied to approach procedure with vertical guidance (APV) phase of flight, an algorithm based on BDS and GPS positioning solution weighted average solution is proposed. Firstly, the algorithm obtains the weighted average solution satisfying the vertical-guided approach by searching for the optimal weight ratio and uses it as the final solution. Then, the distance between the final solution and BDS, GPS positioning solution is used as the test statistic, and the detection threshold is calculated through the maximum allowable false alarm probability. In the end, the fault is detected by comparing the detection statistic and the detection threshold. By collecting the raw GPS/BDS data, the proposed algorithm was verified. The simulation results demonstrate that the proposed algorithm can effectively detect fault satellites.