1.8米望远镜高阶像差测量与补偿

发布时间：2018-01-10 12:00

本文关键词：1.8米望远镜高阶像差测量与补偿　出处：《中国科学院光电技术研究所》2017年博士论文　论文类型：学位论文

【摘要】：在地基大口径望远镜对天体目标进行高分辨力成像观测的过程中,自适应光学系统在对大气湍流进行校正、改善成像质量方面发挥了极其重要的作用。但是,实际应用的自适应光学系统都处于完全未补偿和完全补偿两种极端情况之间,属于部分校正自适应光学系统。自适应光学对于低阶像差可以实现几乎完全校正,但是对于高阶像差校正能力有限,自适应光学系统中不能校正的高阶像差部分是本论文重点讨论的对象。本文的研究背景是基于原1.8米望远镜的127单元自适应光学系统,希望通过测量原有系统无法校正的高阶像差部分,系统的分析影响原有127单元部分补偿系统远场图像质量的因素,研究例如变形反射镜闭环引入的高阶像差、望远镜主光路、自适应光学系统光路中的静态高阶像差,最后通过图像事后处理的方式对静态高阶像差进行精确补偿,以达到提升远场成像质量的目的。同时较系统的分析在建的4米望远镜将来可能面临的无法校正的高阶像差的各个因素。具体工作如下:1.整理分析了天文望远镜中的误差来源对望远镜性能的影响,包括望远镜系统误差和自适应光学系统误差,重点分析了自适应光学中远场图像的构成和自适应光学部分校正获得的图像特性,以及高阶像差对远场图像的影响。2.系统的分析了1.8米望远镜系统自适应光学的当前性能和现有的成像质量,针对高阶像差测量需求分析了影响哈特曼测量精度的误差因素,并设计高阶测量哈特曼波前传感器对1.8米望远镜高阶像差进行测量。确定1.8米望远镜高阶像差测量实验方案,由于其中低阶像差测量光路和高阶像差测量光路是非共光路,所以对其中的非共光路像差提出标定方法,来准确测量系统高阶像差。提出了系统低阶像差和高阶像差测量方案以及系统动态闭环高阶像差测量方案。3.搭建了1.8米望远镜高阶像差测量实验系统,通过测量原有127单元自适应光学系统无法校正的高阶像差部分,分析了1.8米望远镜系统望远镜主光路、自适应光学系统光路中的静态高阶像差情况,以及变形反射镜闭环引入的像差情况,对现有的自适应光学系统校正能力覆盖范围进行了划分,仿真分析了高阶像差补偿后的远场图像。最后提出了1.8米望远镜自适应光学系统高阶像差的补偿设计,通过图像事后处理的方式对静态高阶像差进行精确补偿,达到了提升远场成像质量的目的。4.根据4米望远镜误差分配的要求,对4米望远镜像差控制优化进行了设计。仿真分析了4米望远镜自适应光学系统布局,对变形镜拟合误差、校正行程等进行了估计;分析了自适应光学系统对4米望远镜系统静态像差的校正能力,包括光学加工误差要求、蜂窝镜主镜压印效应分析、系统对准误差要求、次镜支撑筋遮拦要求等,以及对全系统自适应光学校正后的静态残差进行了估计。
[Abstract]:Adaptive optics system plays a very important role in correcting atmospheric turbulence and improving imaging quality in the process of high-resolution imaging of celestial objects by ground-based large-aperture telescopes. The practical applications of adaptive optics systems are between completely uncompensated and fully compensated two extreme cases, which belong to partially corrected adaptive optical systems. Adaptive optics can achieve almost complete correction for low order aberrations. However, the correction ability for higher-order aberrations is limited. The uncorrected high-order aberrations in adaptive optical systems are the focus of this paper. The background of this paper is a 127-element adaptive optical system based on the original 1.8-meter telescope. It is hoped that by measuring the higher-order aberrations which cannot be corrected by the original system, the factors that affect the quality of far-field images of the original 127 unit partial compensation system can be analyzed. For example, the high-order aberrations introduced by the deformable mirror closed-loop, the main optical path of the telescope, and the static high-order aberrations in the optical path of the adaptive optical system are studied. Finally, the static higher-order aberration is compensated accurately by image post-processing. In order to improve the quality of far-field imaging, the factors of uncorrectable higher-order aberrations that the 4m telescope under construction may face in the future are analyzed systematically. The specific work is as follows:. 1. The influence of the error sources on the performance of the telescope is analyzed. It includes telescope system error and adaptive optics system error. The composition of far field image in adaptive optics and the image characteristics obtained by adaptive optics part correction are analyzed. The effects of high order aberrations on far field images. 2. The current performance of adaptive optics and the existing imaging quality of 1.8m telescope system are systematically analyzed. According to the demand of high-order aberration measurement, the error factors affecting Hartmann measurement accuracy are analyzed. A high-order measurement Hartman wavefront sensor is designed to measure the high-order aberration of the 1.8-meter telescope, and the experimental scheme of high-order aberration measurement for the 1.8-meter telescope is determined. Because the low order aberration measurement optical path and the high order aberration measurement optical path are non-common optical path, a calibration method is proposed for the non-common optical path aberration. The system low order aberration and high order aberration measurement scheme and the system dynamic closed loop high order aberration measurement scheme. 3. A 1.8-meter telescope high-order aberration measurement experimental system is built. By measuring the high-order aberrations which cannot be corrected by the original 127-unit adaptive optics system, the static high-order aberrations in the main optical path of the 1.8-meter telescope and the optical path of the adaptive optics system are analyzed. And the aberration caused by the deformable mirror closed-loop, the coverage of the correction ability of the existing adaptive optical system is divided. The far-field images after high-order aberration compensation are simulated and analyzed. Finally, the compensation design of high-order aberration for 1.8-meter telescope adaptive optical system is proposed. The static higher-order aberration is compensated accurately by image post-processing to improve the far-field imaging quality. 4. According to the requirements of error allocation of 4m telescope. The design of aberration control optimization for 4-meter telescope is carried out. The layout of adaptive optical system of 4-meter telescope is simulated and the fitting error of deformable mirror and the correction stroke are estimated. The ability of adaptive optics system to correct the static aberration of 4 m telescope system is analyzed, including the requirements of optical processing error, the analysis of imprint effect of honeycomb mirror primary mirror, and the requirement of system alignment error. In addition, the static residuals of adaptive optics correction for the whole system are estimated.
【学位授予单位】：中国科学院光电技术研究所
【学位级别】：博士
【学位授予年份】：2017
【分类号】：TH751

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