低温红外温差源的设计与研究

发布时间：2018-03-15 23:13

本文选题：低温红外　切入点：黑体温差源　出处：《哈尔滨工业大学》2017年硕士论文　论文类型：学位论文

【摘要】：近年来随着红外系统测量精度的不断提升,太空探索、空间监测等多项工作拥有了更加高效的技术手段。为了保证此类系统的高精度要求,特别是对于应用于深冷太空监测的红外系统,需要为其设计特殊的可模拟此类太空工作环境的红外辐射器完成偏差校正试验并准确测量系统的精度。低温红外温差源就是完成此类试验的方法之一,它的主要作用是对系统的不均匀性进行校正,并对其灵敏度进行测量。本文的主要内容即为低温红外温差源的设计过程以及结果情况分析。低温红外温差源的总体结构主要包括两个主要模块:立式真空室结构和准直系统结构。其中:立式真空室内的黑体背景、黑体目标、靶标以及液氮罐一同为系统提供稳定的低温温差辐射信号,它们是系统的核心元件;准直系统用于模拟太空观测时的光路结构并使信号透射红外窗口提供给被检红外系统。在关键技术的设计中,黑体背景的边长设定为120mm,黑体目标直径保证大于50mm,两者的温差为低温热辐射信号。降温方法为液氮浴法,其结构为面源结构,可选择的致冷板结构包括:圆筒式、空腔式、蛇形管式和蛇形槽式四种结构,根据降温时长以及温度均匀性进行选择。另外,系统根据降温过程以及黑体目标的加热过程确定温度探针以及加热片的分布情况,并采用PLC控温元件实现恒温方案的设计。准直系统的结构为抛物面反射式平行光管,其焦距为704mm,视场为5°;并根据工作波段确定红外窗口采用7-12μm锗红外窗口。并采用次镜离轴式结构,离轴量h等于200mm,可避免中心遮挡的问题。为保证红外温差源系统正常工作,需要对总体系统的杂散光影响情况进行分析,并根据其对辐射的影响确定系统的辐射校正方案,提升低温红外温差源的工作精度。在本文的低温红外温差源的设计中,背景信号可保证在80K以下,目标信号的可变温范围为80-300K,控温精度为0.1K。可以满足红外系统校正不均匀性以及测量灵敏度的要求。
[Abstract]:In recent years, with the continuous improvement of infrared system measurement accuracy, space exploration, space monitoring and other work have more efficient technical means. Especially for infrared systems used in cryogenic space monitoring, It is necessary to design a special infrared radiator that can simulate the working environment of this kind of space. It is necessary to complete the deviation correction test and accurately measure the accuracy of the system. The low-temperature infrared temperature difference source is one of the methods to complete the test. Its main function is to correct the nonuniformity of the system, The main content of this paper is the design process and the result analysis of the low temperature infrared temperature difference source. The overall structure of the low temperature infrared temperature difference source consists of two main modules: vertical vacuum chamber junction. Construction and collimation system structure. Among them: blackbody background in vertical vacuum chamber, Blackbody targets, targets and liquid nitrogen tanks together provide the system with stable low-temperature difference radiation signals, which are the core components of the system. The collimation system is used to simulate the optical structure of space observation and to make the signal transmission infrared window available to the detected infrared system. The side length of the blackbody background is set to 120 mm, the diameter of the blackbody object is guaranteed to be more than 50 mm, the temperature difference between the two is a low temperature thermal radiation signal. The cooling method is liquid nitrogen bath method, and its structure is a surface source structure. The chilled plate structure can be selected as follows: cylinder type, cavity type, In addition, the system determines the distribution of the temperature probe and the heating sheet according to the cooling process and the heating process of the blackbody object. The structure of the collimating system is a parabolic reflective parallel light tube. The focal length is 704mm, the field of view is 5 掳, and the infrared window is determined to be 7-12 渭 m germanium infrared window according to the working band. The off-axis structure of the infrared window is adopted and the off-axis value h is equal to 200mm, which can avoid the problem of central occlusion. In order to ensure the normal operation of the infrared temperature source system, It is necessary to analyze the influence of stray light on the whole system, determine the radiation correction scheme of the system according to its influence on radiation, and improve the working precision of the low-temperature infrared temperature difference source. In the design of the low-temperature infrared temperature difference source in this paper, The background signal can be guaranteed to be below 80K, the variable temperature range of the target signal is 80-300K, and the temperature control precision is 0.1K. it can meet the requirements of the infrared system for correcting the nonuniformity and measuring sensitivity.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TN21

【参考文献】