空间望远镜中快摆镜摆动引起的投影畸变效应  

Projection Distortion Effects Caused by Tip-Tilt of Fast Steering Mirror in Space Telescopes

作　　者：李龙[1,2] 王维 曹智睿[1,2] 孟庆宇 李成浩[1] Li Long;Wang Wei;Cao Zhirui;Meng Qingyu;Li Chenghao(Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences,Changchun 130033,Jilin,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：《光学学报》2024年第11期58-65,共8页Acta Optica Sinica

基　　金：国家自然科学基金(62375264)。

摘　　要：为了提高大口径大视场空间望远镜中精密稳像系统在稳像过程中的稳像精度,本文对精密稳像系统中快摆镜(FSM)摆动引起的投影畸变效应进行了理论分析。从几何光学角度,采用光线追迹法建立了FSM摆动引起的像移计算模型,并从不同视场像点的位移中解析出投影畸变效应;以我国正在建设中的巡天空间望远镜为例,采用CODE V中的光线追迹结果进行交叉验证;根据这一模型,分析了对投影畸变效应可能产生影响的视场大小、FSM行程、FSM到焦面视场中心的距离等因素。结果表明:像移模型的计算精度很高,其计算结果与光线追迹计算结果误差不超过0.01μm;视场大小、FSM行程和中心视场主光线的入射角是影响投影畸变大小的主要因素。本文建立的像移计算模型能够满足实际应用需求,对投影畸变影响因素的分析结果可以为精密稳像系统的设计提供参考依据。Objective Since the Hubble space telescope(HST)was successfully launched in 1990,wide field of view(FOV)and high-resolution sky surveys have become a hotspot in the development of space telescopes under the guidance of the research on dark matter,dark energy,and gravity theory.In large space telescopes with wide FOV,such as the James Webb space telescope(JWST)and the ultraviolet/optical/infrared surveyor(LUVOIR),fast steering mirrors(FSMs)are usually employed in optical systems as the execution mechanism of high-accuracy image stabilization due to their small inertia moment,high positioning accuracy,high bandwidth,and fast response speed.Finally,the vibration and pointing errors reduced by the attitude controlling system of the satellite platform are compensated for additionally to adjust the transient location of the image on the focal plane.However,due to the FSMs located near the exit pupil and in a convergent optical path,the tip-tilt process will also cause the inclination between the optical focal plane and the detector plane,resulting in projection distortion effects.As a result,the motion of the image points caused by the tip-tilt of the FSM at different FOV angles will lose the synchronization,while an additional distortion has been involved,which means decreasing image stabilization precision.Therefore,we theoretically analyze the processing mechanism and influencing factors of the projection distortion effects to determine mitigating methods during the telescope design and further improve the image stabilization accuracy in precise image stabilization.Methods Our analyses are based on the imaging principle of geometric optics.The image point displacement at different FOVs caused by the tip-tilt of FSM is analytically modeled by adopting the ray-tracing method,and the effects of shift,rotation,and projection distortion are demonstrated respectively.Meanwhile,all these parameters involved in the analytical model are determined to be the same coordinate system(focal plane coordinate system)by employing th

关 键 词：望远镜 投影畸变 光线追迹法 齐次坐标变换法 快摆镜 精密稳像 

分 类 号：TH743[机械工程—光学工程]