Collaborative Navigation of a Crosslink-Augmented Lunar PNT Constellation

The Lunar Augmented Navigation Service (LANS) is a planned network of lunar satellite constellations intended as a lunar counterpart to the terrestrial GNSS. The NASA LCRNS, ESA Moonlight, and JAXA LNSS constellations will cooperate to disseminate LunaNet-compatible PNT-over-comms services for lunar users. In order to provide precise PNT services, the constellations themselves must be navigated to a very high degree of accuracy. Recently-reported research by the authors has revealed that the introduction of inter-satellite links (ISL) is a promising method for imparting autonomy and improving accuracy and reliability of navigating such constellations. This paper describes a strategy for precise orbit estimation of a representative lunar PNT constellation. The results demonstrate the efficacy of using ISL to augment the constellation's navigation precision in conjunction with measurement of weak-signal GPS and ground-based ranging.