Autonomous optical navigation for spacecraft around small celestial bodies based on landmarks

Due to abundant craters which are clearly visible and distinguishable existing on surface of small celestial bodies, an autonomous optical navigation algorithm based on navigation landmark using craters for spacecraft around small celestial bodies is discussed. For the problems arising from evidently uncertainty and strongly nonlinear of orbit dynamics models, an autonomous optical navigation algorithm using the Gauss-Markov process and Unscented kalman filter is presented to improve the precision of orbit estimation and ensure the stability of algorithm. Considering the landmarks geometry configuration has great effect in influencing orbit determination precision, singular value and condition number of observation matrix is utilized to analyzing the observability of navigation system, and a novel landmark selecting rule is proposed to improve the precision of orbit estimation. Finally, effectiveness of the proposed autonomous navigation algorithm performance is validated using the numerical simulation.