用于检测双星故障的RAIM算法分析与研究*

随着GPS等卫星导航技术的广泛应用，在实际导航中对接收机的导航定位精度，尤其对定位的有效性提出了越来越高的要求。目前对此较为有效的方法就是利用接收机自主完好性监视(RAIM, Receiver Autonomous Integrity Monitoring)进行保障，而且该方法日益凸显出其优越性，但目前对该方法的研究多基于单星故障的假设。随着新一代导航系统的完善以及组合导航技术的发展，双星甚至多星同时出现故障成为不可避免的话题。本文分析和比较了用于检测两颗卫星故障的偏差完好性风险(BIT, Bias Integrity Threat)法和保护限值(PL, Protection Level)法两种RAIM算法。通过数据仿真，对用不同方法检测卫星故障的可用性及故障检测率进行比较，并分析了两种方法存在差异的理论依据。通过分析比较，说明在未来接收机处理多颗卫星同时出现故障的情况时，如何更精确地描述统计检测量与定位偏差的关系以及如何处理不同测量噪声的影响是RAIM算法可用性及有效性的关键。

Analysis and research of RAIM algorithms for identifying simultaneous two faulty satellites

This paper introduced two RAIM algorithms include PL method and BIT method which were proposed for identifying simultaneous two-faulty satellites. Simulated ground grids, computed and compared the results of RAIM availability and ratio of fault detection. Through comparison and analysis, how to describe the relationship between the statistics and positioning bias, and how to deal with the infection of different measurement noise is the keys for identifying simultaneous two or more faulty satellites availably.