The Performance Assessment on Lunar Navigation for GNSS

With the gradual implementation of China's lunar exploration project, the ground monitoring and control network also has to complete a large number of lunar monitoring and control tasks. In order to alleviate this pressure, lunar spacecraft needs to employ other methods to finish its positioning and timing tasks. Global navigation satellite system is designed to provide positioning and timing service for terrestrial users. Because of the improvement on GNSS receiver, it has been used on LEO satellites and spacecraft. However, the signal power of navigation satellites in GNSS is weak, and GDOP of visible satellites is bad, which is a big challenge for the design of GNSS receiver on lunar orbit. In this paper, the lunar navigation performance of GPS and BDS III is evaluated. We analyzed the propagation attenuation loss of GPS and BDS III signals on the moon, and gave the propagation attenuation of these signals at different frequencies. In addition, we investigated the power variation characteristic, the number variation, visible time, and GDOP of navigation satellites in GPS and BDS, which can improve the design of GNSS receiver for lunar mission.