低轨卫星精密运动学定轨性能差异分析  

Performance of Precise Kinematic Orbit Determination for Different Low Earth Orbit Satellites

作　　者：耿江辉[1,2] 曾竞 赵磊 GENG Jianghui;ZENG Jing;ZHAO Lei(GNSS Research Center,Wuhan University,Wuhan 430079,China;Hubei Luojia Laboratory,Wuhan 430079,China)

机构地区：[1]武汉大学卫星导航定位技术研究中心,湖北武汉430079 [2]湖北珞珈实验室,湖北武汉430079

出　　处：《测绘地理信息》2024年第1期1-9,I0001,共10页Journal of Geomatics

基　　金：国家自然科学基金(42025401)。

摘　　要：基于全球导航卫星系统(global navigation satellite system,GNSS),采用精密单点定位(precise point positioning,PPP)技术的低轨卫星运动学定轨是广泛研究的热点。然而不同低轨卫星搭载星载接收机性能不同,基于其星载GNSS数据的运动学定轨效果也会有所差异。本文首先介绍了GARCE-FO卫星和Swarm卫星及其星载接收机,然后从观测卫星数、伪距多路径以及信号强度对比其数据质量差异,最后基于武汉大学开源的PIRDE PPP-AR软件解算其相应的运动学轨道进行对比。结果表明,GRACE-FO卫星相比Swarm卫星可观测到的GNSS卫星数更多,其各自的伪距多路径分别为0.16~0.19m和0.3~0.44m,并且GRACE-FO卫星的信号强度分布6~9之间,而Swarm卫星L2频率上的信号强度分布在1~7之间。综合来说,Swarm卫星的观测数据质量劣于GRACE-FO。此外,GRACE-FO卫星的模糊度残差表现出良好的近正态分布特性,宽巷模糊度和窄巷模糊度的固定率可达99%和93%,而Swarm卫星的窄巷模糊度残差则分布不规则。与权威机构发布的精密科学轨道对比,GRACE-C在切向、法向和径向3个分量固定解的轨道精度分别为1.39cm、0.98cm和2.59cm,GRACE-D卫星轨道精度与GRACE-C卫星整体一致;Swarm卫星各分量的运动学轨道精度则在3~4 cm左右,相较于GRACE-FO卫星要低1~2 cm。在平差解算时降低参数之间的相关性能有效提高参数估值的精度,使用随机游走估计GRACE-FO卫星的接收机钟差来相较于白噪声在径向分量上有60%左右的提升。此外,欧洲定轨中心(Center for Orbit Determination in Europe,CODE)发布的Swarm卫星运动学轨道以简化动力学解算得到的模糊度作为约束来降低参数相关性,相较于本文解算的运动学轨道在径向分量上也有一定的提升。The precise kinematic orbit determination of low earth orbit(LEO)satellites based on Global Navigation Satel⁃lite System(GNSS)using the precise point positioning(PPP)technology is of interest within GNSS community.However,different LEO satellites carry different spaceborne GNSS receivers with different capabilities,and the kinematic orbit determination based on the GNSS data will also vary.This paper first introduces the GARCE-FO and the Swarm satellites and their spaceborne receivers,then compares their data quality differences in terms of number of observed satel⁃lites,multipath of pseudorange and signal strength,and final⁃ly compares the performance of their corresponding kinematic orbit determination using the PIRDE PPP-AR software from Wuhan University.The results show that GRACE-FO satel⁃lites can track more GNSS satellites than Swarm satellites,and their respective pseudorange multipath distributions are 0.16~0.19 m and 0.3~0.44 m,and the signal strength dis⁃tribution of GRACE-FO satellites is between 6~9,while that of Swarm satellites on L2 frequency is between 1~7.The quality of the observations from the Swarm satellites is poorer than that of the GRACE-FO satellites.In addition,the GRACE-FO residuals of ambiguity show a good zeromean high-peak normal distribution,with fixing rate up to 99%and 93%for wide-lane and narrow-lane ambiguities re⁃spectively,while the Swarm residuals of ambiguity are poorly distributed for narrow-lane ambiguity.Compared to the pre⁃cise science orbit,the orbit accuracy of GRACE-C in the along-track,cross-track and radial-track of the ambiguityfixed solution is 1.39,0.98 and 2.59 cm respectively,and the orbit accuracy of the GRACE-D satellite is consistent with that of GRACE-C.The kinematic orbit accuracy of the Swarm satellite in each component is about 3~4 cm,which is 1~2 cm lower than that of the GRACE-FO satellite.Reduc⁃ing the correlation between the unknown parameters in the ad⁃justment can effectively improve the accuracy of the parameter estimation,hence

关 键 词：低轨卫星 运动学定轨 数据质量对比 精密单点定位 

分 类 号：P228[天文地球—大地测量学与测量工程] V412[天文地球—测绘科学与技术]