INS/CNS Integrated Navigation Method for Circular Orbiting Satellite

Due to the strong complementarity between the Inertial Navigation Systems (INS) and the Celestial Navigation Systems (CNS), the integrated navigation systems of the INS and CNS are widely utilized as autonomous navigation systems for circular orbiting satellites. However, the traditional loosely coupled INS/CNS integrated navigation systems not only limit navigation performance but also lack altitude measurement. To address these problems, a new INS/CNS integrated navigation method, which is composed of a tightly coupled integrated navigation system and an altitude-computed mode, is proposed for circular orbiting satellites. The tightly coupled integrated navigation system is utilized to attain high-accuracy satellite attitude, latitude, and longitude assisted by infrared Earth measurement. The altitude computed system is utilized to calculate the altitude of the satellite. This method can effectively correct the attitude, latitude, and longitude errors, and provide the altitude information as well. The feasibility of this method is tested by stimulation experiments. The results illustrate that this method is extremely effective in navigation estimation and can be used as the navigation system for circular orbiting satellites at different altitudes.