北斗系统双星故障对完好性故障识别的影响

Influence of Beidou Dual-satellite Fault on Integrity Fault Identification

完好性是卫星导航系统检测和识别故障能力的重要指标之一,北斗系统复杂的星座结构为系统故障的检测和识别带来了挑战。文章通过引入双星故障检测模型和伪距偏差组合,仿真实际的北斗卫星导航系统(BeiDou navigation satellite system,BDS)双星同时故障的情况,采用不依赖于参数分布情况的统计检验方法,分析得出:双星故障模式下完好性参数的变化与单星故障模式下完好性参数的变化存在显著差异,特别地,BDS双星故障模式下的完好性参数(水平定位误差和高程定位误差)不服从高斯分布,这使得传统基于单星故障的故障检测和识别方法不适用于双星故障检测;不同双星故障模式对完好性参数的影响存在显著差异。因此,应建立针对不同卫星类型的BDS故障检测和识别模式,提高系统完好性性能。

Integrity is one of the important indicators of fault detection and identification ability in satellite navigation system.The complex constellation structure of BDS(BeiDou Navigation Satellite System)brings challenges to the fault detection and identification.By introducing BeiDou dual-satellite fault model and pseudorange deviation combination,this paper adopts a statistical test method independent of parameter distribution to simulate the situation of dual-satellite fault.The results show that:(1)the pattern of integrity parameters changes under dual-satellite fault mode is significant different from the pattern under single satellite fault mode.In particular,the integrity parameters(horizontal positioning error and vertical positioning error)distribution under dual-satellite fault mode do not follow the Gaussian distribution.Therefore,the traditional fault detection and recognition method based on single satellite fault is not suitable for dual-satellite fault situation.(2)There are significant differences in the influence of different dual-satellite fault modes on integrity parameters.Therefore,different fault identification modes should be established for different satellite types to improve the performance of the system integrity.