一种可检测和改正微小慢变伪距偏差的新RAIM方法  

A New RAIM Method for Detecting and Correcting Weak Pseudo-range Bias under Gradual Change

作　　者：刘文祥[1] 李峥嵘[1] 王飞雪[1] 

机构地区：[1]国防科学技术大学电子科学与工程学院,卫星导航研发中心,长沙410073

出　　处：《宇航学报》2010年第4期1024-1029,共6页Journal of Astronautics

基　　金：新世纪优秀人才支持计划(NECT-04-0995)

摘　　要：在卫星导航系统各种应用场合中,漫反射多路径效应、通道一致性、大气延迟改正模型不精确等多种因素将导致伪距观测量出现微小慢变偏差,使导航接收机的定位精度下降。传统的接收机自主完好性监测(RAIM)方法基于单历元"快照"处理,检测性能依赖于故障卫星伪距偏差,故在检测微小伪距偏差时存在局限性。提出了一种基于多历元积累检测量的新RAIM方法,增大了积累后奇偶矢量的等效伪距偏差,提高了对微小慢变伪距偏差的检测性能,同时还给出了估计与改正伪距偏差的方法。理论分析和仿真结果表明,该方法积累10个历元即可显著改善对微小慢变伪距偏差的检测性能,经过伪距偏差改正后定位精度提高。In the applications of the satellite navigation system,many factors such as the multipath effect of diffuse reflection,the channels＇ mismatching,the un-precision of the atmosphere delay model and so on,cause the pseudo-range weak bias under gradual change and decrease the receiver＇s positioning accuracy.Based on single epoch ＂snapshot＂ processing,conventional receiver autonomous integrity monitoring（RAIM） is limited when detecting the weak pseudo-range bias because its detection performance depends on the fault bias level.This paper presents a new RAIM method based on the several epochs＇ sum test,which augments the equivalent bias of the sum parity vector and shows the better detection performance than the conventional method.Furthermore,a novel method of estimating and correcting weak pseudo-range bias under gradual change is presented.The theoretical analysis and simulation results show that the new method with ten epochs＇ sum provides high performance of detecting weak bias under gradual change and the positioning accuracy is improved remarkably after correcting the pseudo-range bias.

关 键 词：卫星导航系统 接收机自主完好性监测 微小慢变伪距偏差 奇偶矢量 

分 类 号：TN967.1[电子电信—信号与信息处理]