Abstract: The autonomous optical navigation algorithm for spacecraft around Moon using the Gauss-Markov process and Unscented Kalman filter is presented. For the problems arising from the absence of exact orbit dynamics models of spacecraft around Moon, the un-modeled acceleration of orbit dynamics is approximated by using the Gauss-Markov process in order to improve the precision of orbit dynamics. Considering the problems of orbit determination algorithm based on extended Kalman filter, the position, and velocity of spacecraft and the un-modeled acceleration are estimated by using the Unscented Kalman filter to improve the precision of orbit estimation and ensure the stability of algorithm. And the autonomous optical navigation algorithm is validated using the numerical simulation.

Key words: autonomous optical navigation, spacecraft around moon, Gauss-Markov process, Unscented Kalman filter