北斗三号最简系统卫星信号质量分析

Quality Analysis of Satellite Signal for BDS-3 Simplest System

截至2018年5月,中国共发射了8颗北斗三号(BDS-3)中圆地球轨道(medium Earth orbit,MEO)卫星,组成北斗三号最简系统,播发了B1C、B2a和B2b新卫星信号,仅有17个国际全球导航卫星系统监测评估系统(international global navigation satellite system monitoring and assessment system,iGMAS)跟踪站能够接收到BDS-3卫星信号。选用17个iGMAS观测站10 d的观测数据,从数据完整率、信噪比、多路径效应、电离层延迟和周跳方面进行质量分析,并与GPS L1/L5和Galileo E1/E5a重叠频率对比,评价当前BDS-3卫星信号性能以及iGMAS测站的接收能力。结果表明,装有GNSS_GGR接收机的iGMAS测站的伪距观测值含有较大的粗差,个别装有CETC-54-GMR-4011接收机的跟踪站的周跳现象较严重。通过分析多路径效应可知,BDS-3卫星各个信号中不存在与高度角有关的系统偏差。BDS-3最简系统卫星观测数据质量与GPS L1/L5和Galileo E1/E5a相当,能够满足北斗卫星导航系统正常的工作需求。

Eight new-generation BeiDou global satellites(BDS-3)had been launched into medium Earth orbit(MEO)successfully until May 2018.They constitute the BDS-3 simplest system,and transmit several new navigation signals,namely B1 C,B2 a,and B2 b,and only 17 iGMAS tracking stations can track BDS-3 satellite signals.The 10 days real Multi-GNSS data of 17 iGMAS(international global navigation satellite system monitoring and assessment system)tracking stations are selected for quality analysis in terms of data integrity,signal to noise ratio(SNR),multipath effect,ionospheric delay and cycle slip.By comparing with the GPS L1/L5 signals and Galileo E1/E5 a signals,the performance of the current BDS-3 satellites signals and the receiving capability of the iGMAS tracking stations are obtained.The results show that,there are large gross errors in pseudorange observations of iGMAS tracking stations which are equipped with GNSS_GGR receivers,and the cycle slips of several tracking stations equipped with CETC-54-GMR-4011 receivers are serious.The analysis of code multipath shows that the elevation-dependent system biases seem to be not exist for all the available signals of BDS-3 satellites.The observations quality of the BDS-3 simplest system satellites is comparable to that of GPS L1/L5 and Galileo E1/E5 a signals,which can meet the normal working requirements of BeiDou satellite navigation system.