GSSM缩比模型子孔径拼接误差分析（英文）  

Giant Science Steering Mirror Prototype Sub-aperture Testing Error Analysis

作　　者：安其昌[1,2] 张景旭 杨飞[1] 赵宏超[1] 

机构地区：[1]中国科学院长春光学精密机械与物理研究所,长春130033 [2]中国科学院大学,北京100039

出　　处：《光子学报》2018年第1期196-208,共13页Acta Photonica Sinica

基　　金：The Youth Innovation Promotion Association CAS(No.2016198);the National Natural Science Foundation of China(Nos.11403022,11673080)

摘　　要：巨型科学可控反射镜(GSSM)缩比模型(GSSMP)的子孔径拼接误差的分析可以指导GSSM的面形检测工作.GSSMP子孔径拼误差包括子孔径刚体位移误差以及中频扰动.对子孔径刚体位移误差而言,合理的靶标布置以及最小二乘算法的使用,可将误差量级降低到计算机可分辨的最低程度,即不引入算法误差;同时也降低了对测试执行部件的精度要求.对中频扰动误差而言,可结合标准平面镜与干涉仪对实验环境中大气湍流的影响进行估计.除此之外,对子孔径拼接顺序带来的误差进行分析.最后,基于三十米望远镜的面形评价方法,即斜率均方根对上述误差进行换算表征.算法修正后,子孔径对准误差为10^(-6)μrad、子孔径平移误差为10^(-6)μrad、子孔径倾斜误差为10^(-6)μrad以及大气扰动误差为0.04μrad.利用信噪比来表征拼接顺序所带来的影响,使用一个子孔径作为基准进行拼接的情况下,拼接顺序带来的影响小于2%.本文的拼接算法,可以在较低的机械精度下,利用靶标对准与合理的拼接顺序,达到较高的拼接精度.Giant Steerable Science Mirror （GSSM） is largest flat mirror as the tertiary mirror of Thirty Meter Telescope （TMT）.To evaluate the performance of GSSM under gravity load, the mirror figure needs to be tested. Erorr analysis is the most imortant step for the reliability of metrology. For its large size and plate character, Sub aperture stitching will be used to reach the full aperture figure. GSSMP is the prototype of GSSM. Research on GSSMP sub aperture testing error will help understanding and learning how to build GSSM. The stitching error is divided into two parts：rigid body location error and middle frequency turbulence. According to each part, theoretical analysis and experience have been done drawing the conclusion that the algorithm with probable marks will suppress rigid body error efficiently and the influence of the turbulence is achieved by smaller aperture system and interferometer. What is more, stitching order is also related to stitching order. Using one reference aperture and fitting other apertures onto it allow introducing least error to the final result. All the performance is specified by Slope RMS,which is required by TMT.After fitting, Shift error is 10-6 μrad, Piston error is 10-6 μrad, Tip/tilt error is 10-6 μrad and Air turbulence is 0.04 μrad. The error involved by the rigid body is ignorable, and the air turbulence is 3nm in RMS. By Slope MS, the reqiured metric of TMT, the influence of stitching error will be discussed and the orders chosen here did not increase the Signal to Noise ratio significantly in the figure at the level of 2%. Here the conclution was drawed that feature will help a lot in lowering the stitching error.

关 键 词：三十米望远镜 巨型科学可控反射镜原理样机 误差分析 子孔径拼接 

分 类 号：TH751[机械工程—仪器科学与技术]