一种高精度的国家标准时间远程复现方法

A Method of National Standard Time High Precision Remote Reproduction

  • 摘要: 国家授时中心保持的协调世界时UTC(NTSC)(Coordinated Universal Time,National Time Service Center)与UTC的偏差保持在±10 ns以内。为了使远程用户获得高精度的UTC(NTSC)时间频率信号,利用国家授时中心保持的UTC(NTSC)时频信号和卫星共视时间比对方法,搭建了一套UTC(NTSC)远程复现系统,用于实现远程用户时间频率校准并能在远程恢复出UTC(NTSC)的时间频率信号。研究了基于UTC(NTSC)的时间频率远程复现方法,该方法基于改进的卫星共视法,可实现对用户本地参考时间与可视卫星钟的钟差进行连续实时监测,去除了传统共视时间传递方法中每个观测周期内的观测死时间;设计并实现了UTC(NTSC)远程复现系统,系统包括基准终端、配送终端和数据分析处理中心,基准终端测量UTC(NTSC)与可视卫星钟的钟差;配送终端测量本地原子钟与可视卫星钟的钟差,并在本地驾驭生成与UTC(NTSC)同步的时频信号;数据处理中心处理来自基准终端和配送终端的数据;评估了系统测量的不确定度,得出零基线条件下,系统授时精度达到0.8 ns;另外,通过对各远程用户不同类型钟的驾驭情况,得出铯钟的频率测量天稳达到2.84×10-14,铷钟的频率测量天稳达到8.24×10-14

     

    Abstract: The Coordinated Universal Time (UTC) scale maintained at the National Time Service Center (NTSC), is known as UTC(NTSC), with a deviation from UTC of less than ±10ns. In order to enable the remote users access to high precision time as maintained at NTSC, based on the UTC(NTSC) time frequency signal and common-view time comparison method, a set of UTC(NTSC) remote reproduction system is developed to achieve time and frequency calibration as well as establish traceability to UTC (NTSC) for remote users. This paper discusses the following 1) a method based on UTC(NTSC) time frequency remote reproduction, based on improved common-view method, which can realize the measurement of time difference between local reference time and the continuous satellite clock., The dead time in the observation cycle of traditional common-view has been removed.2) Design and realization of UTC(NTSC) remote reproduction system. This system includes a primary terminal, distribution terminals and a data processing center. The primary terminal measures bias between UTC(NTSC) and satellite clocks. The distribution terminal is used to measure the bias between local time and satellite clock, and steer the lock time and frequency signal to synchronize with UTC(NTSC).The data processing center deals with the data from primary terminal and distribution terminals. 3) Analysis of measurement uncertainty, in order to estimate the measurement uncertainty of system, Zero-baseline and long-baseline experiments were carried out. In the zero-baseline experiment, the system timing accuracy was 0.8ns. However, in order to verify that users steering with different types of clocks with the system, the long-baseline experiment shows that the frequency stability (day) of a cesium clock can reach 2.84×10-14, and rubidium clock reaches 8.24×10-14.

     

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