摘要
针对卫星运动对星地距离和钟差测量的不利影响,提出一种基于最小二乘拟合的星地动态双向时间同步与测距算法。在建立星地可视模型基础上,仿真了MEO运动卫星与地面时间同步站之间星地距离的变化规律,分析了卫星运动对星地双向时间同步与测距的主要不利影响。该算法首先利用星地双向时间同步数据分别生成星地距离和钟差拟合多项式,然后联合求解出运动卫星误差最小的星地距离与钟差。实验结果表明了该算法的合理性和科学性,在包含仿真误差的条件下,其时间同步精度优于3 ns,测距精度优于3 m。将其应用到各种空天应用系统的星地时间同步与测距中,可以消除卫星运动对双向时间同步与测距的不利影响,提高时间同步与测距精度。
Aiming at the negative impact of the satellite motion on the measurements of satellite-ground range and clock offset, an algorithm for dynamic satellite-ground two-way time synchronization and ranging based on least square fitting is proposed. On the basis of the establishment of the satellite-ground visible model, the rule of variation of the range between MEO satellite and ground station is simulated, and the main negative impacts of satellite motions on satellite-ground two- way time synchronization and ranging is analyzed. In this algorithm, the satellite-ground range and the clock offset corresponding to minimal error are solved by using the combination of satellite-ground range fitting polynomial and clock- offset fitting polynomial generated by using the data related to satellite-ground two-way time synchronization. Experimental resuhs show that accuracies of time synchronization and ranging better than 3 ns and 3 m can be achieved respectively in the presence simulation error. The algorithm will be used in accurate ranging and time synchronization of various aerospace application systems to eliminate the negative impact of satellite motion on two-way time synchronization and ranging and improve the accuracies of time synchronization and ranging.
出处
《宇航学报》
EI
CAS
CSCD
北大核心
2014年第9期1050-1057,共8页
Journal of Astronautics
基金
国家自然科学基金资助项目(11073022
10673011)
湖南省自然科学基金资助项目(11JJ3072)
湖南省教育厅科学研究基金资助项目(13A115
10C0413)
中国科学院精密导航定位与定时技术重点实验室开放基金资助(2009PNTT07)
长沙市科技计划项目资助(K1309019-11
K1309035-11)
关键词
空天应用系统
卫星通信
双向时间同步
星地测距
Aerospace application system
Satellite communication
Two-way time synchronization
Satellite-groundrange measurement
