Analysis of PNT Algorithms and Related Performance for Lunar Navigation Service Users

Navigation and communication systems will play a key role in supporting lunar exploration missions, by guaranteeing constant contact between astronauts and robotic systems with their respective control centres and by ensuring the correct and accurate surface positioning of exploration vehicles and the navigation services during the cruising and landing phases of shuttles travelling between Earth and the Moon. In the framework of the ESA’s Moonlight initiative, Telespazio leads one of the two Lunar Communication and Navigation Service (LCNS) Projects. LCNS aim to establish an infrastructure for lunar communication and navigation services with the goal to decrease the cost and complexity of future human and robotic lunar missions by offering a range of commercial navigation and communication services. This paper has the objective to show the results of the study carried out by Telespazio, focused on the development of the positioning algorithms based on the navigation service architecture defined in the LCNS project. Three relevant lunar navigation scenarios are addressed: low altitude lunar orbits, landing and surface navigation. For each scenario, the positioning algorithms exploit different sensors and rely on specific implementation of Kalman filtering. Extensive numerical simulation exercises were carried out to test the performance of the navigation filters for the different scenarios. The findings obtained with the simulations for the different scenarios, as well as the details of the implementation, are reported in the paper. The performance attained by the three filtering implementations provided good results with respect to the user requirements concerning the accuracy of the position solution. Therefore, this study appears as a promising starting point to exploit more efficient positioning algorithms and other possible sensor fusion strategies dedicated to the future LCNS users.