Acta Geodaetica et Cartographica Sinica ›› 2020, Vol. 49 ›› Issue (3): 269-277.doi: 10.11947/j.AGCS.2020.20180534

• Geodesy and Navigation •     Next Articles

BeiDou wide-area precise timing prototype system

SHI Chuang1,2, ZHANG Dong1,2, SONG Wei1,2, YU Jialiang2, GUO Wenfei3   

  1. 1. School of Electronic and Information engineering, Beihang University, Beijing 100083, China;
    2. Laboratory of Navigation and Communication Fusion Technology, Ministry of Industry and Information Technology, Beijing 100083, China;
    3. GNSS Research Center, Wuhan University, Wuhan 430079, China
  • Received:2018-11-20 Revised:2019-11-28 Published:2020-03-24
  • Supported by:
    The Key Program of National Natural Science Foundation of China (No. 41931075);The Specific Project of Chinese Satellite Navigation System(GFZX030302030204);The General Program of National Natural Science Foundation of China (No. 41974038)

Abstract: In recent years, the time transfer method based on precise point positioning (PPP) shows a superior performance in terms of accuracy and coverage, which has made it become one of the most popular GNSS time transfer methods. As the timeliness of wide-area differential products improves, real-time PPP time transfer has been applied to the study of precise timing. On the basis of PPP time transfer, this paper introduces a wide-area precise timing(WPT) system based on BeiDou satellite navigation system (BDS). We applied real-time PPP time transfer, time-frequency control and hardware delay calibration technology in this system, which could ensure that users can obtain accurate, stable and traceable time in real time.The WPT system consisted of time service platform and terminal. The platform introduced high-accuracy time as the reference time of the system. At the same time, it provided real-time wide-area differential correction data. The terminal obtained the difference between the local clock and the system time based on PPP method. Then steering clock technology was used to realize time synchronization between terminal and system. In order to verify the real-time timing performance of the system, this paper conducted performance testing and evaluation in zero baseline, short baseline and wide-area environments. The experimental results show that the accuracy of time synchronization in the condition of zero baseline and short baseline is better than 0.5 ns. And timing accuracy in a single day is better than 1 ns in a single day, which provide a reference for the development of precision timing technology based on BeiDou system.

Key words: time transfer, wide-area precise timing system, satellite clock offset estimation, clock steering, hardware delay calibration

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