基于NIMDO及光纤传递的高精度时间同步系统研究

Study of High Precision Time Synchronization System Based on NIMDO and Optical Fiber Transfer

针对公安交管部门对时间同步的需求,研究和设计了一种高精度的时间同步系统。该系统基于NIMDO进行卫星共视数据比对,实现时间标准向基准的实时溯源、实时同步,并结合光纤传输技术、精确时间协议和网络时间协议,向公安交管部门进行城域分级时间传递。通过对系统进行验证及分析,NIMDO与UTC(NIM)时间偏差测量结果中90.53%在±5ns以内,98.60%在±20ns以内;系统中时钟单元与时间标准的时间偏差在单纤双向传递时测量结果为-4.45~4.85ns,在双纤双向传递时测量结果为5.01~24.99μs,在采用网络时间协议时的测量结果为0.64~4.60ms。结果表明该系统解决了时间溯源和同步问题,可为其它领域的时间同步提供参考。

A high precision time synchronization system was studied and designed which aimed at synchronizing time in public security traffic management department. The system based on NIMDO traced and synchronized time standard to UTC(NIM) in near real time by satellite common-view method. It transferred time standard hierarchically to public security traffic management department,which combined with optical fiber transfer technology,precise time protocol and network time protocol. The results of validation and analysis showed that 90. 53% of the time offset between NIMDO and UTC(NIM) maintained within ± 5 ns and 98. 60% maintained within ± 20 ns;the time offset between the clock units and the time standard were-4. 45 ~ 4. 85 ns when the single-fiber bidirectional transfer was used,5. 01 ~ 24. 99 μs when doublefiber bidirectional transfer was used,0. 64 ~ 4. 60 ms when network time protocol was used. The results showed that the system solved the problem of time traceability and synchronization,and can provide reference for time synchronization in other fields.