基于星间距离变化的动态双向时间同步算法

An Algorithm of Dynamic Two-way Time Transfer Based on Intersatellite Range Variation

以卫星双向时间同步算法为基础,分析了运动卫星之间的双向时间同步信号传播延迟随星间距离的变化特点,推导了按此算法计算得到的卫星钟差随星间距离的变化规律,提出了一种利用星间伪距拟合多项式和钟差拟合多项式联合求解高精度星间钟差的卫星动态双向时间同步算法。实际卫星的仿真数据表明,该算法能够把星间的时间同步误差控制在5 ns以内,可用于星间高精度时间同步。

Presently The algorithm of two-way satellite time transfer is one of the time synchronization methods with the highest accuracy. On the basis of two-way satellite time transfer algorithm, the characteristics of the propagation delay of two-way time transfer signals between moving satellite varying with intersatellite range were analyzed, and the rule of satellite clock offset varying with intersatellite range obtained with this algorithm was deduced. This paper presents a dynamic two-way time transfer algorithm with which high-accuracy intersatellite clock offset is solved through the combination of intersatellite pseudo-range polynomial fitting and clock offset polynomial fitting. Simulation data of actual satellites showed that with the algorithm the intersatellite time synchronization error can be controlled within 5ns. As a result the algorithm can be used for intersatellite high-accuracy time synchronization.