Navigation Doppler lidar sensor for precision landing of China's Chang'E-5 lunar lander.

Lidar technology is playing an important role in the application of autonomous navigation and hazard avoidance for the landing and cruising exploration on planetary bodies, such as landing on the moon, Mars, and asteroids. We report a Doppler lidar developed for Chang'E-5 mission in this paper. To meet high reliability and resource constraints, time-sharing measuring and in-phase and quadrature processing in this Doppler lidar system was provided and tested. Compared with the traditional linear frequency modulated systems, this lidar system provides excellent detection probabilities of false alarms, especially for the determination of velocity directions. Flight and vibration tests and plume experiments were carried out to further demonstrate the performance and feasibility during the landing mission in late 2020.