Analysis of GNSS Multi-constellation Time Transfer Accuracy

Abstract

Timing service is an indispensable part of national economy, and timing technology directly restricts the accuracy of time obtained by users. High precision time transfer technology is an indispensable technology for time synchronization in all time laboratories. In this paper, based on GNSS multi-constellation precise single point positioning (PPP) technology, a time transfer method based on GNSS quad-constellation was proposed, and the precision satellite orbit and clock difference products provided by IGS were used for time transfer accuracy and frequency stability analysis. The experimental results show that the GNSS multiple constellation PPP can complete the time transfer of the accuracy of nanosecond. The PPP time transfer accuracy of GPS/BDS/GLONASS three-system combination is improved to a certain extent compared with GPS single system and GPS/BDS two-system, while the precision of GPS/BDS/GLONASS/Galileo four-system is not improved obviously compared with three-system. Through the analysis of the satellite data for 4 consecutive days, it is found that the inter-station clock difference solution calculated by GNSS multi-constellation PPP can reach the frequency stability of $5 \times 10^{ - 13}$–$6 \times 10^{ - 13}$, which is in good frequency consistency with the clock difference product released by IGS.