GNSS实时动态授时精度分析

基于GNSS载波相位观测值的实时动态授时，可有效规避PPP授时对实时精密轨道和钟差产品的依赖问题，对短距离动、静态高精度时间用户具有重要意义。为了更好地验证GNSS实时动态授时性能，基于中国科学院国家授时中心时间频率资源和三个GNSS跟踪站长达2个月的观测数据，以GPS系统为例开展了授时试验。与事后PPP时间传递相比，实时动态授时结果差异STD优于0.15ns；与光纤双向时间传递结果相比，实时动态授时结果差异STD优于0.5ns。试验表明，GNSS实时动态授时精度能够达到亚纳秒量级，可为下一步推广应用提供重要参考。

Accuracy analysis of GNSS real-time kinematic timing

Compared with PPP timing, real-time kinematic timing based on GNSS carrier phase observations can effectively avoid dependence on real-time precise orbit and clock products, and is of great significance to short-distance kinematic and static high-precision time users. In order to verify the performance of GNSS real time kinematic timing, a timing experiment was carried out with the GPS system as an example based on the time and frequency resources as well as the observation data of three GNSS tracking stations for up to 2 months of the National Time Service Center of the Chinese Academy of Sciences. Compared with the PPP time transfer, the standard deviation of differences from real time kinematic timing result is better than 0.15ns; compared with the result of optical fiber two-way time transfer, the standard deviation of differences from real-time kinematic timing result is better than 0.5ns. The experiments show that GNSS real time kinematic timing accuracy can reach the sub-nanosecond level, which can provide an important reference for the future application of this timing technique.