GPS电文用户测距精度参数设计分析  

Term design and analysis of user range accuracy in GPS navigation message

作　　者：王陆潇[1,2] 黄智刚[1] 赵昀[1] 

机构地区：[1]北京航空航天大学电子信息工程学院,北京100191 [2]重庆邮电大学通信与信息工程学院,重庆400065

出　　处：《南京理工大学学报》2014年第5期620-625,共6页Journal of Nanjing University of Science and Technology

基　　金：国家自然科学基金(60879012/F01);国家"863"计划(2009AA12z329)

摘　　要：为了研究卫星导航系统完好性参数设计对用户端完好性的影响,该文对GPS电文完好性参数中用户测距精度(URA)参数的分级方式及用户算法的变化进行了研究。采用实际国际GPS服务(IGS)广播电文数据与精密星历星钟数据进行仿真分析,证明了细化GPS用户测距精度分级方式的必要性。在此基础上,证明了采用相互独立的星历和星钟用户测距精度值能更好地描述卫星段误差。考虑传输段误差影响,利用广播星历构造卫星星座仿真分析了最坏用户位置处的测距误差,并采用加权法和最大方差法分别计算用户瞬时测距精度。对电文改进前后的两种区间划分标准和不同URA更新周期下的用户测距精度索引值进行比较分析。研究结果表明,导航电文采用5 bits将用户测距精度细化为32个区间能更好地区分不同卫星的测距误差,改善用户的完好性性能。To study the impact of the integrity terms design on the user integrity performance for the satellite navigation system, the integrity parameter fractional resolutions and user algorithm of the user range accuracy（URA） parameters of the GPS message are studied here. By means of the broadcast and the precise ephemeris collected from the international GPS service （IGS）, the change necessity of the URA index and the cabinet mode is proved. The independent ephemeris and clock URA index are proved to be able to describe the satellite error characteristic better. The satellite constellation is obtained from the broadcast ephemeris. The user range error at the worst user location in the service volume is simulated taking into account the propagation errors, and its index is calculated by the weighted method and the maximal variance method, and its indices are compared and contrast with different URA update intervals with and without improvements respectively. The research results demonstrate the further fractionized 5 bits URA index with 32 binning structures can discriminate the satellite errors and improve user integrity performance.

关 键 词：卫星导航系统 完好性 用户测距精度 保护水平 

分 类 号：TN967.1[电子电信—信号与信息处理]