精导星传感器设计

Design of a Fine Guidance Sensor

精导星传感器广泛地应用于空间红外天文望远镜中,它利用光学系统的长焦距及相关算法获得高精度像移,实时地为精密稳像控制系统提供补偿信息。本文详细介绍了精导星传感器的设计过程:设计了与载荷共光路的光学系统成像方案,选择了适合在深低温环境下工作的碲镉汞探测器作为精导星传感器(Fine Guidance Sensor,FGS)探测器,采用基于专用集成电路(Application Specific IntegratedCircuit,ASIC)的前置电路代替了传统印刷电路板(Printed Circuit Board,PCB)电路,设计了科学观测中的精导星功能;为了满足精导星传感器高精度实时检测的需求,选择ROI-IDFT 矩阵乘法运算对相关峰及其附近区域进行变换,避免冗余计算,降低了运算量。最后,本文总结了精导星传感器在工程实现中亟待解决的关键技术以及应用前景。

Fine guidance sensors have been widely used in space infrared telescopes by utilizing extremely long optic system focal length and a correlation algorithm to provide image motion for a vibration compensation mechanism.This paper introduces the design procedure of the fine guidance sensor,explicitly.We employed a strategy with the payload central field of view as an optical system,an HgCdTe detector as a fine guidance sensor detector,cold front-end electronics based on ASIC in place of a conventional PCB,and a custom FGS guidance function for astronomical observations.It requires the subpixel centroid algorithm to have high accuracy and high speed performance.To meet the above-mentioned requirements,we propose an algorithm based on ROI-DFT.The transformation is focused on the region of interest by IDFT matrix multiplication,which eliminates the need for redundancy calculation,thereby improving its computational efficiency.In summary,this paper highlights the key technologies that urgently need to be solved,as well as their applications in the future.