基于环境温度反馈的卡塞格林望远镜自动调焦  

Automatic focusing of Cassegrain telescope based on environmental temperature feedback

作　　者：管雯璐 谭逢富 靖旭 侯再红 吴毅 GUAN Wen-lu;TAN Feng-fu;JING Xu;HOU Zai-hong;WU Yi(Key Laboratory of Atmospheric Optics,Anhui Institute of Optics and Fine Mechanics,Hefei Institutes of Physical Science,Chinese Academy of Sciences,Hefei 230031,China;University of Science and Technology of China,Hefei 230026,China;Advanced Laser Technology Laboratory of Anhui Province,Hefei 230037,China)

机构地区：[1]中国科学院合肥物质科学研究院安徽光学精密机械研究所中国科学院大气光学重点实验室,安徽合肥230031 [2]中国科学技术大学,安徽合肥230026 [3]先进激光技术安徽省实验室,安徽合肥230037

出　　处：《光学精密工程》2021年第8期1832-1838,共7页Optics and Precision Engineering

基　　金：国家自然科学基金资助项目(No.41405014)。

摘　　要：为了在望远镜设备探测过程中实时调节由环境温度变化引起的光学系统组合焦距偏离,建立了温度与成像焦点位置调节的对应关系。通过理论计算得出卡塞格林望远镜系统组合焦距变化与温度变化的关系,利用步入式可编程高低温箱设计了温度实验,得出系统单位温度焦点位置的变化量,并在实际工作环境下进行了二次标定,得出望远镜设备的离焦量为-0.14 mm/℃。最后,结合理论实验设计了一种基于环境温度反馈的望远镜自动调焦装置,应用于设备外场观测实验,得出自动调焦装置使用前后望远镜系统的成像信噪比。实验结果表明,离焦量与温度变化量具有相关性,调焦装置使用后所成图像的均方根误差由5.056降低为0.729,成像信噪比由41.09提高到49.50。环境温度反馈的自动调焦技术有利于望远镜设备更好地捕捉观测目标,抑制背景噪声,提高信号采集的精确度与参数测量的准确度,增强了外场探测对环境温度变化的适应能力。To adjust the combined focal length deviation of an optical system caused by the changes in environmental temperature in real time during telescope equipment detection,this study established the relationship between the temperature and variation in the imaging focus position. Through theoretical calculations,the relationship between the focal length change of a Cassegrain telescope system and temperature change was obtained. Then,a temperature experiment was conducted using a walk-in programmable high and low temperature box. The change in the focal position per unit temperature of the system was obtained. A second calibration was conducted in the actual working environment. The defocus of the telescope equipment considered in this study was-0. 14 mm/℃. By combining theoretical and experimental results,a telescope automatic focusing device based on environmental temperature feedback was designed. Finally,the device was applied to an equipment field observation experiment. We obtained the imaging signal-to-noise ratio of the telescope system before and after the automatic focusing device was applied. The results demonstrated that the defocus corresponded to the temperature change. After the focusing device was incorporated,the mean square error of the resulting image was reduced from 5. 056 to0. 729,and the imaging signal-to-noise ratio was increased from 41. 09 to 49. 50. The automatic focusing technology of environmental temperature feedback helps the telescope system to better capture the observation target,suppress background noise,improve the accuracy of signal acquisition and parameter measurement,and enhance the adaptability of external field detection to environmental temperature changes.

关 键 词：望远镜 组合焦距 环境温度 自动调焦 

分 类 号：TP391[自动化与计算机技术—计算机应用技术]