Reliability and Backup Strategy Analysis of Low-Earth Orbit Navigation Constellation

In order to realize the requirement of stable operation of Leo Navigation system, redundant backup of constellation system should be designed in constellation networking stage and constellation operation stage respectively. A certain number of satellites to be launched should be backed up on the ground ahead of time to ensure system reliability is maintained above a certain level. In this paper, by comparing several kinds of reliability calculation methods of constellation system and the strategy of constellation network supplement, the optimal scheme of accuracy and calculation resource consumption is selected synthetically. The author complete design the number of satellite backup and launch plan in the operation phase based on requirements of different levels of single satellite reliability and system reliability. In this paper, author apply Monte Carlo method multiple sampling to the life distribution of a single satellite and compare it with the real-time operating hours of satellites in orbit to obtain the current system reliability, which can be used to obtain the constellation system reliability at any time and get different network backup strategy. The analysis results show that this method can provide a quantitative basis for the design and optimization of the backup strategy of navigation constellation.