Dual-Satellite Lunar Global Navigation System Using Multi-Epoch Double-Differenced Pseudorange Observations

Abstract

In view of the upcoming missions to obtain resources from the lunar surface, it is essential to have highly-accurate navigation systems to locate surface vehicles in shadowed regions. In response, we propose a dual-satellite lunar navigation system that is based on a multi-epoch double-differenced pseudorange observations (MDPO) algorithm. We used multi-epoch observations in a new way that reduces the number of navigation satellites required. In addition, the double-differenced pseudorange is used in order to eliminate the bias effects of the satellite and user clocks that conventional dual-satellite navigation algorithms did not fully take into account. Furthermore, a pre-known lunar digital elevation model is used to reduce the number of observations. The theoretical behavior of the MDPO algorithm was confirmed by simulation and the results indicate that user position accuracy can be several tens of meters with 95% probability (2drms) within a one-minute observation.

Keywords

• GNSS
• navigation
• microsatellite
• nanosatellite
• moon
• lunar rover