Abstract:The traditional receiver autonomous integrity monitoring(RAIM) algorithm carries out fault detection and identification based on least squares residuals method. Due to the ill-conditioned coefficient matrix problem of least squares residuals method, it may lead to missed detection and missed exclusion. Therefore, we propose an improved RAIM method based on internal coincidence accuracy. Based on the original fault detection method, this method introduces the test threshold of satellite positioning internal coincidence accuracy, and improves the traditional fault detection method to reduce the missed detection rate and improve the fault identification rate. The experimental results show that the improved method can effectively reduce the missed detection rate and efficiently identify faulty satellites without affecting the availability of system integrity algorithms. Compared to the missed detection rate of 4.66% and 1.95% of the traditional algorithm in this experiment, the improved algorithm can reduce the missed detection rate to 2.21% and 0.81%.