Chapter 42 Realization and Performance Analysis of Time and Frequency Remote Calibration System

摘要

On the basis of traditional GPS common-view, Continuous Comparison Technique of Time and Frequency (CCTTF) had been put forward by National Time Service Center (NTSC). 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 for remote users. The design idea and framework of TFRCS are described in this paper, and the data processing of near real-time common-view is presented. Moreover, the experiments of short baseline comparison and long baseline comparison are designed to calibrate the measurement system and test the performance of TFRCS; meanwhile, the measurement uncertainty has been analyzed. The experimental results show that high-precision comparison of time and frequency has been realized by TFRCS, which can be used to establish traceability to UTC (NTSC) for remote users. Time is measured with a combined expanded uncertainty of less than 14 ns, and the frequency is measured with a combined expanded uncertainty of less than 1.5 × 10~(-13) after 1 day of averaging.