广播星历旋转误差对低轨星载BDS-3/GPS实时精密定轨影响分析  

Effects of broadcast ephemeris rotation error on real-time orbit determination for a low Earth orbit satellite using onboard BDS-3/GPS observations

作　　者：李敏[1] 王煜斌 李文文[1,2] 蒋科材 陈国 赵齐乐[1] LI Min;WANG Yubin;LI Wenwen;JIANG Kecai;CHEN Guo;ZHAO Qile(GNSS Research Center,Wuhan University,Wuhan 430079,China;Department of Land Surveying and Geo-Informatics,The Hong Kong Polytechnic University,Hong Kong,China)

机构地区：[1]武汉大学卫星导航定位技术研究中心,武汉430079 [2]香港理工大学土地测量与地理资讯学系,中国香港

出　　处：《导航定位与授时》2024年第1期43-52,共10页Navigation Positioning and Timing

基　　金：国家自然科学基金(42004020,42074032,42030109,42204020,42204019)。

摘　　要：基于LT-01A卫星星载BDS-3/GPS观测值进行了星载实时精密定轨研究,并重点分析了广播星历旋转误差对实时定轨精度的影响。通过赫尔默特转换评估了所选时段内GPS和BDS-3广播星历轨道旋转误差,显示BDS-3广播星历旋转误差可达-8.7 mas,平均量级较GPS大约2.5倍。BDS-3广播星历经旋转改正后,轨道切向、法向均方根(RMS)误差从25 cm左右提升至10 cm量级,提升幅度超过50%。因此,基于星载BDS-3以及BDS-3/GPS联合的实时定轨精度受BDS-3星历旋转误差影响严重,且主要作用于切向和法向。经过旋转改正后,单独BDS-3实时定轨在切向、法向、径向RMS分别为21.0 cm、10.7 cm及11.2 cm,其切向和法向精度比改正前分别提升15.0%和31.8%;BDS-3与GPS联合定轨进一步提升切向精度至19.4 cm。得益于BDS-3广播星历较高的精度,单BDS-3以及BDS-3/GPS联合的实时定轨在旋转改正前的三维RMS分别为31.9 cm和29.2 cm,较单GPS实时定轨分别提升9.1%和16.8%;添加旋转改正后,其定轨精度分别提升至26.7 cm和25.0 cm,较单GPS实时定轨分别提升22.6%和27.5%。The real-time orbit determination(RTOD)performance with onboard BDS-3 and GPS observations from a Chinese low Earth orbit satellite,LT-01A,is analyzed,with a focus on the impact of broadcast ephemeris rotation error on RTOD accuracy.The orbit rotation errors of GPS and BDS-3 broadcast ephemeris are evaluated by Helmert transformation with respect to post precise orbit product.BDS-3 broadcast ephemeris reveals rotation errors reaching up to-8.7 mas,and indicates an average rotation error about 2.5 times larger than that of GPS.After the rotation correction of BDS-3 broadcast ephemeris,the root mean square(RMS)errors in the along-track and cross-track components of BDS-3 broadcast ephemeris show significant reductions from about 25 cm to a level around 10 cm,manifesting an improvement by more than 50%.Therefore,the RTOD accuracy based on spaceborne BDS-3 and BDS-3/GPS combination are significantly affected by the rotation error of BDS-3 ephemeris,which mainly degrades the along-track and cross-track components.For BDS-3 only RTOD,the along-track,cross-track,and radial RMS errors with rotation correction are 21.0 cm,10.7 cm,and 11.2 cm,respectively;the along-track and cross-track accuracies present improvements by 15.0% and 31.8%,respectively.By combining BDS-3 and GPS observations,the RTOD errors at the along-track components are further improved to 19.4 cm.Thanks to the high accuracy of BDS-3 broadcast ephemeris,the three-dimensional RMS errors of independent BDS-3 and combined BDS-3/GPS RTOD are 31.9 cm and 29.2 cm,respectively,which are 9.1% and 16.8% smaller than GPS-only RTOD errors,respectively.With rotation correction,the orbit determination accuracies are improved to 26.7cm and 25.0cm,respectively,which is 22.6% and 27.5% smaller than those of single GPS real-time orbit determination.

关 键 词：低轨卫星 北斗三号 广播星历 实时精密定轨 旋转误差 

分 类 号：P228.4[天文地球—大地测量学与测量工程]