基于接收机钟差的GPS完好性自主检测算法

传统的基于最小二乘法和奇偶矢量的接收机自主完好性检测（Receiver Autonomous Integrity Monitoring, RAIM）算法均是利用冗余观测量进行一致性检验实现的，其检测统计量均由伪距残差构造得到。本文采用接收机钟差作为RAIM算法的判据，基本思想是根据钟差历史解算值建立接收机钟差二次多项式模型，从而得到当前时刻的钟差预测值。同时解算当前时刻的钟差值，将这两者之差与钟差门限值进行比较来判断系统当前时刻是否存在故障。本文首先分析了伪距偏移量对接收机钟差的影响，然后给出确定钟差门限值的方法。结合用户解算位置和接收机钟差利用子集比较法实现了故障识别的功能。因本文给出的故障检测算法不是基于冗余观测量的，故该方法在四颗可见星下就可进行故障检测，与传统的RAIM算法相比降低了RAIM算法对可见星个数的要求，该点在实验部分进行了仿真验证。另外还对可用星多于四颗的基于接收机钟差的RAIM算法进行了故障检测和故障识别部分的仿真，验证了本文方法的可行性。

A Receiver Clock Bias-Based GPS RAIM Algorithm

The conventional RAIM algorithms based on least square method and parity vectors both utilize pseudo-range residuals to develop test statistics.To use these methods,redundant pseudo-range measurements are necessary.Different from the previous algorithms,the clock bias is selected as a criterion of the RAIM algorithm which does not need redundant pseudo-range measurements.An analysis of the impact of pseudo-range bias vector on receiver clock bias is provided on the basis of the proposed method.And then a me...