Performance Evaluation and Comparison between Spaceborne Atomic Clocks of BDS-3 Satellites and Other GNSS Systems

The spaceborne atomic clock is the basis for determining the time base of satellite.The Beidou-3 (BDS-3) and other global satellites were analyzed in terms of accuracy,drift and stability using one year’s post-event precise clock error data to evaluate the in-orbit atomic clock of the Global Navigation Satellite System (GNSS). The results show that the accuracy of the rubidium clock of BDS-3 and the hydrogen maser are in the range of 2.62×10^-13~2.54×10^-11and 1.64×10^-14~6.77×10^-11 respectively.The frequency drift of the hydrogen maser of BDS-3 is much better than that of rubidium clocks.In terms of stability,most hydrogen masers of BDS-3 can reach the order of 10^-15.The average frequency stability value of BDS-3 is the best,followed by Global Positioning System (GPS), Beidou-2 (BDS-2), Galileo and GLONASS.