Abstract:

Direct sensing horizon and indirect sensing horizon are two typical kinds of autonomous celestial navigation method.  Direct sensing horizon is simply and reliable, but the navigation precision that depends mainly on earth sensor is lower.  Indirect sensing horizon gets horizon information by observing atmosphere refraction stellar using the star sensor.  Because the numbers of refraction stellar and observing time are limited, the observed information is discontinuous. A  new method of autonomous celestial navigation using both of the two methods based on information fusion is presented. The  new information is imported when refraction stars cannot be observed. Simulation results show that the proposed method  can improve the precision and reliability of the navigation system.