弹载捷联星敏感器强光规避策略及算法

星敏感器光学系统及成像阵列易受太阳和月亮强光干扰.针对弹载捷联星敏感器提出一种规避强光的解析几何方法.通过天文公式解算出观星时刻太阳、月亮矢量，将其转换到当地地理坐标系下；将太阳、月亮方位、地心指向和星敏感器圆视场的几何分布关系划分为3种类型，并结合星敏感器遮光罩太阳月亮规避角参数，分别建立矢量公式求解星敏感器光轴的指令指向；利用STK仿真软件进行算法验证，选择任意时间段并设定星敏感器光轴指向，经本算法解算的光轴指令指向均可成功规避太阳月亮和地平.该算法可实现星敏感器光学系统的自主保护、观星窗口的选择，可以通过姿态机动实现太阳和月亮的规避和有效星光观测.

Strategy and Algorithm on Evasion of Sunlight and Moonlight for Missile Borne Strapdown Star Tracker

Attitude determination of star tracker is executed by observing star light, which is rather weak, the optics and the imaging array are not applicative to the sun and the moon, the two strong light sources in the space, so a geometrical analytic method is put forward for star tracker to evade strong light sources. First, the sun and moon direction vectors at the observing time are calculated according to the astronomical equations and converted to the local geographic coordinate system. Then, the geometrical relationships among the direction vectors of the sun, the moon the geocenter and the conical FOV of star tracker are divided into 3 classes totally, combined with the exclusive angle parameters of the sunlight and of the moonlight designed for the baffle, the vectorial equations are built for each case to solve the command boresight orientation to direct the following attitude maneuver. Finally, the algorithm verification is carried out using STK (Satellite Tool Kit). The simulation environment is set up by selecting a spell of time and settling the boresight orientation of the star tracker, to conduct a scenario that has more chances for the Sun and the Moon lights interfering into the star tracker FOV or the baffle. After many times of tests, the commanded orientation of the boresight by the algorithm always succeeds in evading the sun, the moon and the horizon plane. This method can conduct protecting of the optics of the star tracker autonomously, selection of star observation window, and can carry out the valid starlight observation by the evasion of the Sun and the moon through attitude maneuver.