Celestial navigation system is an important autonomous navigation system widely used for deep spaceexploration missions, in which extended Kalman filter and the measurement of angle between celestial bodies areused to estimate the position and velocity of explorer. In a conventional cartesian coordinate, this navigationsystem can not be used to achieve accurate determination of position for linearization errors of nonlinear space-craft motion equation. A new autonomous celestial navigation method has been proposed for lunar satellite usingclassical orbital parameters. The error of linearization is reduced because orbit parameters change much moreslowly than the position and velocity used in the cartesian coordinate. Simulations were made with both the cart-esiane system and a system based on classical orbital parameters using extended Kalman filter under the sameconditions for comparison. The results of comparison demonstrated high precision position determination of lunarsatellite using this new method.
