基于星间测距的导航卫星自主定轨新算法  

A new autonomous orbit determination algorithm based on inter-satellite ranging measurements

作　　者：陈艳玲[1,2] 胡小工[1] 周善石[1] 宋小勇[3] 黄勇[1] 毛悦[3] 黄珹[1] 常志巧 吴杉 

机构地区：[1]中国科学院上海天文台,上海200030 [2]大地测量与地球动力学国家重点实验室,武汉430077 [3]西安测绘研究所,西安710054 [4]北京卫星导航中心,北京100094

出　　处：《中国科学：物理学、力学、天文学》2015年第7期70-77,共8页Scientia Sinica Physica,Mechanica & Astronomica

基　　金：国家自然科学基金(批准号:11103068;11203059);大地测量与地球动力学国家重点实验室项目(编号:SKLGED2014-4-5-E);上海市空间导航与定位技术重点实验室(编号:12DZ2273300)资助项目

摘　　要：受限于星载计算机处理能力,目前导航卫星自主定轨多采用序贯、分布式的定轨算法.但该类算法在节省计算资源的同时存在滤波发散与精度指标快速下降的问题,尤其在链路数量较少的情况下更为突出.本文提出一种快速、稳定的集中式自主定轨新算法.该算法借助空时分多址(STDMA)体制强大的高频星间测距功能,不依赖于动力学建模,在短弧内将卫星的真实轨道与长期预报轨道的差异用高阶次多项式描述,无需轨道积分和状态转移矩阵计算,算法极为简洁,大大节省了计算资源.同时,此算法还通过约束卫星升交点赤经实现了无锚固站支持条件下的自主定轨,减少了对地面支持系统的依赖程度.最后,仿真北斗全球导航系统星间链路测量,论证了星间链路数量、星间测量噪声对导航星座自主运行性能的影响,并对其计算量进行了理论分析.仿真结果证明,本文算法无误差积累,稳定性较高,在链路数少至3条时自主定轨也能够平稳运行;在链路数量?5时,不考虑地球自转参数(EOP)长期预报误差,自主运行60 d,轨道的用户距离精度(URE)平均为0.9 m,而总计算量仅为扩展Kalman滤波(EKF)分布式算法的七分之一.Due to the limitation of onboard computer＇s relatively low storage and processing ability, current autonomous orbit determination （OD） algorithms mostly adopt sequential and distributed method for navigation satellite. Such algorithms can save computing resources, however have met the problem of filter divergence and rapid accuracy decline especially under the condition of less inter-satellite links （ISLs）. This paper proposes a new rapid and stable centralized algorithm based on powerful high frequency inter-satellite measurement capability under the space/time-division multiple access （STDMA） system. This approach describes the difference between the real and long term forecasting orbit as the simple higher order polynomials, which needs no complex dynamic modeling, trajectory integration and the state transition matrix calculation, thus greatly saves computing resources. Meanwhile, this paper advances to make full use of the longitude of the ascending node information of forecast orbit so as to reduce the dependence on ground support system. Finally, we simulate the Beidou global constellation structure and ISL measurements, demonstrate the impact of the number of ISL, the noise of ISL on the performance of autonomous OD, and analyze the total amount of computation theoretically. The simulation results show that the algorithm with high stability has no error accumulation, and can run normally even with 3 ISLs, and under the condition of no less than 5 ISLs, the orbit user orbit error （URE） is about 0.9 m after 60 days autonomous operation. The total amount of calculation of the new method is theoretically one-seventh of the distributed extended Kalman filter algorithm.

关 键 词：自主定轨 星间测距 集中式运动学统计算法 升交点赤经 URE 

分 类 号：TN96.1[电子电信—信号与信息处理]