地基大口径望远镜重力弯曲引起的指向变化检测与修正  

Measurement and calibration of optical axis changes caused by gravity for ground-based large-aperture telescope

作　　者：王洪浩[1,2] 王建立 陈涛[1] 曹玉岩[1] 陈宝刚[1] WANG Honghao;WANG Jianli;CHEN Tao;CAO Yuyan;CHEN Baogang(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,China;University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]中国科学院长春光学精密机械与物理研究所,吉林长春130033 [2]中国科学院大学,北京100049

出　　处：《光学精密工程》2022年第23期3021-3030,共10页Optics and Precision Engineering

基　　金：天文联合基金资助项目(No.U2031126)。

摘　　要：随望远镜口径的不断增大,望远镜的结构尺寸相应增加,重力场引起的望远镜光轴指向变化影响也愈发明显,对地基大口径望远镜的指向检测与修正是获取高精度轨道目标数据的必要前提。为了实现望远镜指向误差的估计、测量及主动修正,从望远镜的光机系统结构出发,分析了引起望远镜光轴变化的因素,提出了光轴变化检测与修正方法。实验结果表明,在望远镜低仰角情况下,光轴最大相对变化为126″,望远镜桁架结构的重弯曲影响是引起俯仰角相关指向变化的主要因素。以4 m口径望远镜为例,提出基于次镜调整结构及卡式系统零彗差点理论的修正模型来提高望远镜的跟踪性能,修正后望远镜光轴的最大相对变化在3″内。该地基大口径望远镜指向变化检测与修正方法可应用于实际望远镜的标定和装调。As the diameter of ground-based telescopes increases,the structural size of the telescope also in⁃creases accordingly,and the effect of the telescope′s optical axis pointing caused by gravity becomes in⁃creasingly pronounced.The measurement and calibration of optical axis changes for ground-based large-ap⁃erture telescopes is a necessary prerequisite to obtaining high-precision orbital target data.To realize the estimation,measurement,and active correction of the telescope pointing error,the optical axis changing rules of the telescope system are analyzed from the structure of the telescope′s opt-mechanical system,and an optical axis change measurement and calibration method of the is proposed.The experimental results show that the maximum relative change of the optical axis is 126″when the telescope is at low elevation.The main factor causing the pointing change is the effect of gravity on the telescope truss structure.Final⁃ly,a calibration model based on the secondary mirror adjustment structure and the coma-free theory of the Cassegrain system is proposed to improve the tracking performance of the 4-meter aperture telescope.The maximum relative change in the optical axis of the telescope after calibration is within 3″.According to the test results,the ground-based large telescope pointing change measurement and calibration method can be applied to the calibration and mounting process of the telescope.

关 键 词：地基望远镜 大口径 指向变化 跟踪精度 主动修正 

分 类 号：TP273[自动化与计算机技术—检测技术与自动化装置] TH703[自动化与计算机技术—控制科学与工程]