单站GPST/GLONASST时差监测研究

Study on the Time Difference between GPST and GLONASST with Single Monitoring Station

精密定时/授时是全球导航卫星系统(GNSS)中重要的一部分。每个GNSS都维护有自己的参考时间,尽管他们都向协调世界时溯源,但各系统间可能存在着几十甚至几百ns的偏差。要充分利用各个系统的卫星资源进行统一定位和授时服务就必须准确确定各个系统间的时差。文中分析了基于空间信号法的单站时差监测原理,提出了利用GPS/GLONASS多模双频接收机输出的两个系统的观测数据、导航电文以及标准共视数据监测GLONASST与GPST的时差方法。利用BIPM T公报公布的相关数据对130d的时差监测结果进行了评定。结果表明,130d中,时差监测结果消除系统差后与T公报结果最大偏差优于8ns,证明监测结果是有效可用的。

Precise timing is an important part of Global Navigation Satellite Systems （GNSS）. Each of GNSS has independent internal reference timescales. The residual offset of these timescales may reach tens of nanoseconds. In order to realize the interoperability and compatibility of these systems, it is necessary to account the offset among these systems. The theory of monitoring GNSS time offset by the Signal-in-Space at the single monitoring station is analyzed. The offset between GPST and GLONASST in 130 days is taken into account by using the data from a GPS/GLONASS combined receiver, then the mo- nitoring result is estimated/tested by the related data published by BIPM through the circular T bulletin. The test shows that the max residual offset between monitoring result and circular T bulletin data in the 130 days is 8 nanoseconds. It turns out the algorithm is effective and usable.