Abstract: There are many navigation sensors onboard a satellite.The main question is how to manage and use the information they supplied.Combining two or more navigation systems with information fusion technology and optimal estimation theory becomes the trend of the navigation techniques.It takes full advantage of the system complementarily.A satellite autonomous orbit determination system which composed of star tracker,infrared horizon sensor,radar altimeter and ultraviolet sensor was put forword.Base on that system,a federated kalman filter and a new information fusion algorithm were presented.The simulation results verify that this method can obtain high accuracy and reliability.The divergence of filter can be controlled.The calculation speed and convergence speed to the whole system also can be improved.

Key words: Combined navigation, Information fusion, Kalman filter, Satellite