Autonomous navigation system based on sun-earth-moon orientation information with earth's oblateness correction

Two methods of Earth orientation determination are proposed by using dual cone earth sensor in this paper. One is based on the assumption of spherical earth, and for the other method the effects of earth's oblateness is considered. A least square navigation algorithm with earth's oblateness correction is also presented in this paper. Monte-carlo simulation results show that the navigation algorithm with earth's oblateness correction can achieve of position accuracy 800 m (3σ) and 2.4 m/s (3σ) velocity accuracy under measurement noises of 0.1°(3σ) for the earth sensor and 0.05°(3σ) for the sun and moon sensor.