Abstract:
Objectives Under the background of the nanosecond or even sub-nanosecond requirements for timing accuracy proposed by the new generation of communication technology, precise measurement and control as well as military weapon platforms, the wide-area precise timing (WPT) system based on BeiDou satellite navigation system (BDS) is built with sub-nanosecond time service capability.
Methods Based on the WPT prototype system, we further extend the BDS high-precision time-frequency service, including time reference traceability, real-time clock comparison and online monitoring of timing terminal performance, which are of great significance for high-precision timing, real-time comparison and the reliability of timing terminals. The timing performance of BDS high-precision timing terminals in short baseline, medium-length baseline and long baseline is evaluated.
Results The results show that: (1) The accuracy of GPS timing based on WPT service system accuracy is better than 0.1 ns, while the accuracy of BDS-3 is 0.15 ns. The frequency stability of timing results after traceability can reach 1×10－15 at ten thousand averaging. (2) The performance of real-time comparison for BRUX-SPT0 link based on WPT is better than 0.1 ns. (3) The difference between the terminal time and the system time is less than 1 ns. (4) The accuracy of real-time time synchronization for short and medium baseline is within 0.1 ns. The frequency stability can reach 1×10－15 level at ten thousand averaging. (5) The accuracy of real-time time synchronization using BeiDou high precision timing terminal for long baseline is better than 1 ns.
Conclusions The WPT service system can provide time and frequency services of better than 100 picoseconds and 1×10－15 magnitude. On this basis, we investigate three application research on BDS high-precision time-frequency services, online metrology of time-frequency terminals, time synchronization of low-orbit constellations and time-frequency test analysis, which are of great significance for BDS innovative applications in the time-frequency field.
下载:
