基于定位误差估计减少RAIM误警的方法

A Method for Reducing the False Alarms of RAIM Based on the Estimation of Position Error

在GPS接收机自主完好性监测(RAIM)中,卫星出现伪距偏差可能导致检测量超限而实际定位误差不超限的误警。我们提出一种减少误警的方法,该方法是在检测和识别故障后,估计定位误差并将其与误差告警限值比较。用一组实测GPS星历数据进行仿真试验,试验结果表明,这种方法减少误警的能力和伪距偏差有关。当伪距偏差较小时此方法的误警率小于传统RAIM算法,当伪距偏差较大时和传统RAIM算法的误警率相当。

When a pseudo range bias occurs in Receiver Autonomous Integrity Monitoring of GPS, the satellite may cause a false alarm that the actual position error doesn＇t exceed the alert limit although the test statistic exceeds the threshold. This paper provides a method of reducing the false alarms after the position error is estimated and compared with the alert limit after the detection and identification procedure. The simulation to verify the method with the actual GPS ephemeris data is carried out , and the result of simulation shows that the ability of reducing the false alarms of the method depends on the pseudo range bias. When the pseudo range bias is small , the false alarming rate of the method is smaller than that of conventional method of RAIM. When the pseudo range bias is large , the false alarming rate of the method is the same as that of conventional method of RAIM.