中国科学院国家授时中心保持的协调世界时UTC(NTSC)性能居于国际前列。基于该条件及GPS共视时间传递技术,提出了时间频率连续比对方法并根据此方法研制了时间频率远程校准系统,用于实现远程用户时间频率校准及向UTC(NTSC)的高精度溯源。首先,阐述了时间频率远程校准系统的设计思想和框架,并对远程用户通过该系统向UTC(NTSC)实现时间频率溯源的过程进行了分析;然后,对系统的时间不确定度和频率不确定度进行了估计。分析结果说明,系统的合成扩展时间不确定度优于14ns,合成扩展频率不确定度优于2.6×10-13,可较好的完成远程用户向UTC(NTSC)的高精度溯源。
The coordinated universal time (UTC) maintained at national time service center (NTSC) ,is known as UTC (NTSC). On the basis of GPS common-view, continuous comparison technique of time and frequency (CCTTF) has been put forward. With this method, time and frequency remote calibration system (TFRCS) has been designed and realized to achieve time and frequency calibration as well as traceability to UTC (NTSC) for remote users. At first,the design idea and framework of TFRCS are presented. Moreover, the process of traceability using TFRCS for remote user is analyzed. Finally,the time and frequency uncertainty of TFRCS are estimated according to designed experiments and relative information. The analysis shows that time is measured with an uncertainty of less than 14 ns and frequency is measured with an uncertainty of less than 2. 6 × 10-13 by TFRCS, which is able to achieve traceability with high accuracy for remote users.