A new method for high-precision starlight refraction indirect horizon-sensing positioning of atmospheric flight vehicles

The starlight refraction indirect horizon-sensing positioning method is a new type of autonomous celestial navigation method with broad application prospects. In view of this method currently being limited to the spacecraft outside the atmosphere, this article derives and establishes a starlight refraction indirect horizon-sensing positioning model between the starlight refraction angle and the flight vehicle’s position inside the atmosphere. Based on this model, a new starlight refraction indirect horizon-sensing positioning method for the flight vehicle inside the atmosphere is proposed. According to the atmospheric refraction law and the spherical atmospheric model, the refracted optical path of starlight entering the atmosphere and reaching the flight vehicle is traced, so as to establish a starlight refraction positioning model that reflects the relationship between the refraction angle and the 3-D position of the flight vehicle inside the atmosphere. Subsequently, by employing star sensors on the flight vehicle to measure the starlight refraction angle, and combining the starlight refraction positioning model that maps the starlight refraction angle and the flight vehicle’s position, a starlight refraction indirect horizon-sensing autonomous celestial positioning method, tailored for the flight within the atmosphere, is proposed. Finally, the effectiveness of the proposed method is verified through ground semi physical experiments, and an analysis is conducted to explore the factors that affect the positioning accuracy of the starlight refraction indirect horizon-sensing positioning method within the atmosphere.