Swarm低轨卫星星座的GPS接收机差分码偏差估计  

GPS Differential Code Bias Estimation Using Swarm LEO Constellation Onboard Observations

作　　者：林高宇 王磊 何飞扬 宋晓迪 郭际明[1] LIN Gaoyu;WANG Lei;HE Feiyang;SONG Xiaodi;GUO Jiming(School of Geodesy and Geomatics,Wuhan University,Wuhan 430079,China;State Key Laboratory of Information Engineering in Surveying,Mapping and Remote Sensing,Wuhan University,Wuhan 430079,China)

机构地区：[1]武汉大学测绘学院,湖北武汉430079 [2]武汉大学测绘遥感信息工程国家重点实验室,湖北武汉430079

出　　处：《武汉大学学报（信息科学版）》2023年第1期119-126,共8页Geomatics and Information Science of Wuhan University

基　　金：国家自然科学基金(41704002,42074036);中央高校基本科研业务经费项目(2042022dx0001)。

摘　　要：差分码偏差(differential code bias,DCB)是指由全球导航卫星系统(global navigation satellite system,GNSS)信号接收和发射硬件导致的频率相关的偏差项,对电离层估计有显著的影响,在利用GNSS观测数据提取电离层总电子含量时需要被精确修正,研究利用低轨卫星的星载GNSS观测数据估计DCB尤为重要。使用Swarm星座3颗卫星GPS接收机2016年1月的双频观测值,设计了独立估计和联合估计两种估计方案,采用附加限制条件的间接平差方法对GPS卫星以及星载接收机的DCB进行估计。以中国科学院和德国宇航中心的DCB产品作为参考,分析了两种估计方案的精度和稳定性,相较于独立估计方案,联合估计方案得到的GPS卫星DCB的稳定性较独立估计方案提高了16.6%,且与参考DCB具有更好的一致性。Objectives:The differential code biases(DCBs)have a great influence on the estimation of ionosphere with GPS observations,which should be precisely calibrated when obtaining ionospheric slant total electron content(STEC).With the increasing number of low-orbit satellites,DCB estimation of low earth orbit(LEO)receivers becomes particularly important for the topside ionosphere research.Methods:Based on the onboard observations of GPS satellites by the Swarm constellation,two different estimation schemes for three satellites in constellation are designed,including individually estimation and combined estimation.Results:Taking the DCB products provided by Chinese Academy of Sciences(CAS)and Deutsches Zentrum für Luft-und Raumfahrt(DLR)as reference values,we analyze the accuracy and stability of these two strategies.Compared with the individual estimation strategy,the combined estimation strategy achieves more stable satellite DCB with a stability improvement of 16.6%for GPS satellites,and the satellite DCB presents better consistency with the reference DCB provided by the two analysis centers.Conclusions:Both strategies can be used to estimate DCB and the combined estimation strategy results in better performance.

关 键 词：低轨卫星 差分码偏差估计 Swarm卫星 参数估计 GPS 

分 类 号：P228[天文地球—大地测量学与测量工程]