组合大视场星敏感器自主定轨中的星光折射

就组合大视场星敏感器卫星自主定轨方法中的恒星观测,在球形大气假设下,直接由大气折射率、光在大气中的折射路径和斯涅耳定律出发,建立星光大气折射模型。在60 km高度以上星光穿过时不产生大气折射的假设下,得到星光在60 km高度的大气层上的仰角θ60、星光折射角γ和星光切线高度h的关系,且当星光穿过20~60 km的高度大气范围时,θ60的范围约在0°~7°之间。最后应用该大气折射模型进行了轨道确定仿真,说明折射模型的有效性。

The Starlight Refraction in Autonomous Orbit Determination for Satellite By Large Field of View Star Sensors

By supposing the atmosphere is of spherical symmetry,starlight refraction model is given deriving from atmospheric refractive index, refractive path in atmosphere and Snell law for the observing method by large field of view star sensors in autonomous orbit determination. On the assumption that the starlight refraction does not happen on the spherical surface whose altitude is larger than 60 km, the relations among the elevation angle θ60 of starlight on atmospheric altitude of 60 km, the starlight refraction angle γ and the starlight tangent altitude h are obtained. And the result shows that range of change of θ60 is from 0°to 7°. At last, the orbit determination simulation is done using this refraction model, and the validity of the model is shown.