摘要
北斗卫星导航系统(BDS)地面跟踪站都配置有高精度的氢原子钟,并基于精密定轨数据处理与主站的时间基准进行同步.在卫星轨道机动以及机动恢复期间,通常采用几何法定轨以及单星定轨确定卫星的轨道.而在这两种定轨模式中,需要提供精确的测站钟差作为输入.为提高定轨的实时性,需要对测站钟差进行预报处理.分析了2次多项式模型、附加周期项模型、灰色模型3种模型对北斗地面跟踪站钟差短期拟合和预报的性能,并将钟差预报结果应用于单星定轨,同时还分析了不同预报钟差用于定轨的精度.试验发现,以上3种模型对6个测站钟差的平均拟合精度分别为0.14 ns、0.05 ns、0.27 ns,预报1 h的平均精度分别为1.17 ns、0.88 ns、1.28 ns,预报2 h的平均精度分别为2.72 ns、2.09 ns、2.53 ns.采用3种模型对测站钟差进行预报并用于单星定轨,采用附加周期项的钟差预报模型轨道3维误差最小,不同模型轨道径向精度差异在3 cm以内.以上结果表明,附加周期项的站钟拟合及预报模型在北斗系统机动期间的轨道恢复数据处理具有最好的效果.
BDS(Bei Dou Navigation Satellite System) ground tracking stations are equipped with high accuracy atomic clocks, and they are synchronized with the BDS time scale(BDT) via the Precise Orbit Determination(POD) processing. During the periods of satellite maneuver and post-maneuver, station clocks are kept fixed as known values in the POD processing. To improve the real-time POD capability, station clocks need to be predicted. In this paper, the performance of three clock prediction models are evaluated, including quadratic polynomial model(QP), periodical term model(PM),and grey model(GM). The precision of clock fitting and prediction, as well as the performance of the prediction models in POD are compared. Data of six stations are used for test, and the results show that: the mean fitting accuracy of quadratic polynomial model, periodical term model, and grey model are 0.14 ns, 0.05 ns, 0.27 ns,respectively;the 1 h and 2 h prediction precision of the three models are 1.17 ns, 0.88 ns,1.28 ns, and 2.72 ns, 2.09 ns, 2.53 ns, respectively. Applying the 1 h and 2 h predicted station clocks in the POD, the 3D orbit accuracy reaches the best using the periodical term model, while the radial accuracy of satellite orbit is rather close for the three models with the difference within 3 cm.
作者
陈倩
陈俊平
于超
张益泽
CHEN Qian;CHEN Jun-ping;YU Chao;ZHANG Yi-ze(Shanghai Astronomical Observatory,Chinese Academy of Sciences,Shanghai 200030;University of Chinese Academy of Sciences,Beijing 100049;School of Astronomy and Space Science,University of Chinese Academy of Sciences,Beijing 100049;Department of Maritime System Engineering,Tokyo University of Marine Science and Technology,Tokyo 1358533)
出处
《天文学报》
CSCD
北大核心
2020年第2期51-61,共11页
Acta Astronomica Sinica
基金
国家自然科学基金项目(11673050)
国家重点研发计划项目(2018YFB0504300)
广东省重点研发计划项目(2018B030325001)资助。
关键词
钟差预报
谱分析
附加周期项模型
定轨
clock error prediction
spectrum analysis
periodical term model
orbit determination
