反射式点光源设备可用于光学遥感器的在轨调制传递函数检测和绝对辐射定标等,其高精度指向是确保太阳光反射至遥感器入瞳的关键。通过进一步提高指向精度,可以减小现有点光源的体积和质量,具有重要的工程意义。通过建立几何误差标校模型和反射镜法向标校模型,去除旋转矩阵参数的相关性;利用阻尼Gauss-Newton方法迭代求解标校模型参数,实现了反射式点光源优于0.1°的指向精度。该研究为实现光学卫星遥感器的高精度、高频次、全动态范围的定标检测提供了基础。

Reflected point light source equipment can be applied to on-orbit modulation transfer function detection and absolute radiometric calibration of optical remote sensors. Its high-precision pointing is the key to ensure the sunlight reflect to the entrance pupil of remote sensors, and the improvement of pointing accuracy can reduce the size and weight of current point light source, which has great importance in practice. A geometric error calibration model and a reflector normal calibration model are established, and the dependence among parameters of the rotation matrix is eliminated. Damping Gauss-Newton method is applied to iteratively solve the model parameters. A pointing accuracy better than 0.1° for reflected point light source is obtained. The study will lay the foundation for high accuracy, high frequency, and full dynamic range calibration of optical satellite remote sensors.