实时星场模拟器中的坐标变换

Coordinate Transformation in Real Time Star Field Simulator

星模拟器是一种在地面上模拟星空，以便对飞行器的姿态识别系统－星敏感器进行功能测试的实验装置．星模拟器必须根据卫星在轨的位置，实时生成对应部分的天空星图，这就有一个坐标变换的问题．证明了对恒星方位来说，从地心天文坐标系到姿态坐标系的转换无需顾及坐标平移所带来的误差，即姿态坐标系可移至地心，只需考虑旋转变换．最后推导出实用的坐标变换公式。

The star simulator is an experimental device on the ground that imitates starry sky so as to test the function of flight vehicles′attitude identification system star sensor. It can produce the corresponding star maps on the basis of the in orbit positions of the satellites, which there is a problem of coordinate transformation. In this paper, the error produced by the coordinate translation is unnecessary to take into account when the coordinate is transformed from an earth celestial coordinate into an attitude coordinate ,that means the origin of the attitude coordinate can be moved to the earth center, only rotate transformation need to be taken into account .At last the coordinate transformation formulas are deduced and the real time star maps are drawn up.