Time service through BD GEO satellites

The Space segment of BeiDou(Compass) global navigation satellite system consists of the 5 Geostationary Earth Orbit (GEO) satellites and 30 Non-GEO satellites (Medium Earth Orbit (MEO) satellites and Inclined Geo Stationary Earth Orbit (IGSO) satellites). At present the Beidou system (BDS) has begun to regional services based on the GEO satellites and the IGSO satellites. The range of services is covering China and neighboring countries and area. There are 5 GEO satellites on orbit. Users can receive the BeiDou system time which is steered to the UTC through the UTC(NTSC) by GNSS CV and TWSTFT. The time service performance of the BeiDou system is concerned by the time users. In this paper, the BeiDou system is introduced firstly, then the satellite time service and the data processing methods are analyzed, based on the analysis, the time service performance of the 5 GEO satellites is discussed, and the results show that eliminating the ionospheric delay and reducing the impact of the troposphere and relativistic effects, the time service performance of the 5 GEO satellites are all stable and their accuracy is quite close to 10ns which can meet the needs of the vast majority of high-precision time users.