星地距离变化对星地双向时间比对的影响及改正

The Influence and Correction of Satellite-to-ground Range Variation on Two-way Time Comparison between Satellite and Ground Station Clocks

星地时间同步是卫星导航系统的关键技术,星地双向时间比对能有效提高星地时间同步的精度。在分析了星地距离变化对星地双向时间比对可引起百纳秒量级误差后,提出了前后历元观测数据差分改正方法,通过数学仿真验证该方法能达到纳秒量级精度。

Satellite and ground station time synchronization is the key technology of navigation satellite system. Two-way time comparison method between satellite and ground station clocks can improve the accuracy of satellite and ground station time synchronization effectively. By analyzing the influence of sateUite-to-ground station range variation on two-way time comparison, which is the source of hundred nanoseconds error, a method of observe data differential correction was presented. Numerical simulation performed later shows that this method can reach the level of nanosecond precision.