联合少量地面控制源的空间信息网轨道确定与时间同步  

Orbit determination and time synchronization of spatial information network combining sparse regional ground stations

作　　者：陈锐志 蔚保国 王甫红[2] 龚学文[2] 鲍亚川 王磊 刘万科[2] 付文举 CHEN Ruizhi;YU Baoguo;WANG Fuhong;GONG Xuewen;BAO Yachuan;WANG Lei;LIU Wanke;FU Wenju(State Key Laboratory of Information Engineering in Surveying, Mapping and Remote Sensing, Wuhan University, Wuhan 430079, China;School of Geodesy and Geomatics, Wuhan University, Wuhan 430079, China;State Key Laboratory of Satellite Navigation System and Equipment Technology, Shijiazhuang 050081, China)

机构地区：[1]武汉大学测绘遥感信息工程国家重点实验室,湖北武汉430079 [2]武汉大学测绘学院,湖北武汉430079 [3]卫星导航系统与装备技术国家重点实验室,河北石家庄050081

出　　处：《测绘学报》2021年第9期1211-1221,共11页Acta Geodaetica et Cartographica Sinica

基　　金：国家自然科学基金重点支持项目(91638203);国家重点研发计划(2016YFB0502200,2016YFB0502201)。

摘　　要：全球低轨卫星通信星座的发展以及全球导航卫星系统卫星轨道和钟差确定技术的进步,为地基连续运行参考系统(CORS)向近地空间转移提供了必要的基础。空间信息网中低轨卫星节点的使用有助于突破地面参考站布设范围的限制,联合少量境内地面控制源可实现全球高精度空间基准服务。针对空间信息网具有的高动态、网络重构性和伸缩性强的特点,如何利用境内少量地面控制源准确确定空间信息网中低轨卫星轨道和时间基准,是实现天基CORS网全球服务的关键。本文研究了基于骨干网和接入网策略进行空间基准和时间基准统一的方法。试验表明,仅利用5个中国境内测站和2个南北极测站,结合12个低轨卫星节点,即可实现约7 cm精度的骨干网中导航卫星和低轨卫星精密轨道确定。在精确确定骨干网节点轨道的条件下,其他节点的实时定轨精度可达10 cm左右。在空间信息网的时间同步体系方面,提出了网络分层自治策略和新型星间链路用于星间和星地高精度时间比对的方法。结果表明基于通信信号体制可实现10 ns精度量级的时间同步性能。The development of global low earth orbit(LEO)satellite communication constellations and the technology advancement of global satellite navigation system(GNSS)orbit and clock determination lay a necessary foundation for moving the continuous operation reference system(CORS)to near-Earth space,which is helpful to break through the limitation of ground reference station distribution and realize global space-based CORS positioning service with few regional ground stations.However,space information network has many different characteristics such as high dynamics,network reconstruction,and significant flexibility.How to determine the orbit of LEO satellites and time datum for a space information network with few regional ground stations is the key to realize global high-precision positioning service of the space-based CORS network.This paper studied the method of unifying space and time datum determination based on the backbone network and the access network strategy.Experiments show that an orbit determination accuracy of about 7 cm is achievable for GNSS and LEO satellites with only five ground stations in China,one in Arctic,one in Antarctica,and 12 LEO satellites.Based on the known precise orbit of space nodes,about 10 cm accuracy is realized for other LEO space nodes that did not participate in orbit determination.For the time synchronization of space information network,the inter-satellite and satellite-ground time comparison method is proposed with the strategy of network layering autonomy and new inter-satellite link.Results show that the time synchronization of 10 ns precision level can be achieved with communication signal system.

关 键 词：时间基准 空间基准 低地球轨道 轨道确定 全球卫星导航系统 

分 类 号：P228[天文地球—大地测量学与测量工程]