【作者】 吕世良；

【导师】 贾平； 刘金国；

【作者基本信息】 中国科学院研究生院(长春光学精密机械与物理研究所) ， 光学工程， 2013， 博士

【摘要】 航天测绘在军事国防和国民经济建设等领域中的广阔应用，促进了航天测绘相机的快速发展。为解决在无地面控制点的情况下，提高航天测绘精度，提出利用传输型三线阵CCD立体测绘相机进行测绘，这种测绘方式具有直接在轨立体成像，并且能从摄取图像重构外方位元素的特点，因而在航天测绘领域占据越来越重要的地位，深受航天大国研究机构的重视。而高精度调焦是航天测绘相机成像清晰及提高测绘精度的关键技术，调焦系统是测绘相机的重要组成部分。本文在某型号星载三线阵CCD立体测绘相机研制背景下，对星载三线阵CCD立体测绘相机的调焦技术及调焦系统实现进行了深入分析研究，主要研究工作有如下几点：1、根据光学系统成像原理，建立线阵CCD相机推扫成像模型并对关键技术指标进行分析，详细分析了导致航天相机离焦原因及离焦对相机MTF的影响程度，分析研究了离焦对测绘相机测绘精度的影响。2、针对三线阵CCD立体测绘相机光机结构组成和工作原理，分析了三线阵CCD立体测绘相机的三条线阵CCD空间严格平行性对调焦系统调焦精度性能要求，根据三线阵CCD立体测绘相机光学系统组成设计特点和相机线阵CCD焦平面结构特点，提出适用于三线阵CCD立体测绘相机的调焦系统方案，并详细阐述了调焦系统组成和调焦工作原理，对调焦范围、调焦步长选择和焦深进行了深入计算分析。3、三线阵CCD立体测绘相机的调焦系统是集光学系统、机械结构支撑、电气控制等环节组成于一体的复杂光机电控制系统，根据调焦应具有稳定性、快速性和准确性的要求，对调焦系统各个组成部分进行详细设计和分析，确定调焦电机驱动电路和工作频率；根据CCD焦平面的特点和调焦精度要求，详细设计了三级减速传动机构，计算各级传动比、调焦电机灵敏度和编码器的灵敏度，并根据误差分析合成理论，计算出调焦系统理论设计误差；针对调焦功能需求，在对遍历搜索法和爬山算法进行分析基础上，提出并实现粗调焦细调焦相结合的调焦算法，并根据调焦算法详细设计开环调焦控制和闭环调焦控制软件流程；提出适合三线阵CCD立体测绘相机的三台相机之间调焦互相比对的调焦策略，并对这种策略中的两种对比调焦法进行了阐述。4、研究了调焦系统光机结构和控制系统集成装配和调焦标定测试。在实验室内对调焦系统的调焦行程、调焦精度、调焦行程内CCD焦平面的直线性和旋转性进行详细测试，测试结果满足三线阵CCD立体测绘相机对调焦系统的技术指标要求，验证了调焦系统设计合理性和实用性。在空间环境模拟器里模拟测绘相机在轨工作环境，对相机进行热光学试验，利用调焦系统测试出五种典型温度情况下测绘相机MTF值随着CCD焦平面位置变化特性曲线；然后根据测试数据分析出相机最大MTF值及对应CCD焦平面位置与温度对应关系，作为相机在轨调焦的重要依据。更多还原

【Abstract】 Spaceflight mapping has broad application prospects in the military, nationalconstruction and other fields, which promote spaceflight mapping camera to developradpidly.The transmission type three line CCD mapping camera was proposed,because it can improve the mapping accuracy in area, where there are no groundcontrol points. The three line CCD mapping camera has the merits that it can getinflight stereo imaging, and it can reconstruct the exterior orientation elements fromthe imaging.Thus three line CCD mapping camera play more important role in thefield of spaceflight mapping, and many more researcher study on the kind of spacephotography. While focusing technology is one of the key technologies in thedevelopment of spaceflight mapping camera. As a important component of spaceflightmapping camera, focusing system determine not only the image quality but also themapping accuracy. With the research on a project of three line CCD mapping camera,this thesis emphasized on discussing the focusing technology, the design andrealization of focusing system for the three line CCD mapping camera.The specificstudy in this thesis are as follow:1. The optical system imaging principle of spaceflight camera was analyzed, andthe push-broom imaging model for line CCD camera was established, key technicalindicators was also analyzed. The reasons of defocusing was discussed in details forspaceflight camera. The influence degree for MTF and mapping accuracy leading toby defocusing was discussed and analyzed. The focusing evaluation function based onMTF and power spectrum was proposed.and simulated. 2. The composing and imaging principle for three line array CCD mappingcamera was introduced, and the three line CCD space strict parallel converted to theCCD focal plane was analyzed in the technical requirements Focusing scheme wasproposed for the three linear CCD mapping camera. The components and workingprinciple of focusing system was introduced.3. The focusing system is a set of optics, mechanics, electrics aspects of thecontrol system, the focusing performance should be stable, quick and precision.Therefore, the various components of the focusing system was designed and analyzedin detail to ensure that the focusing precision meet the requirement of three line CCDmapping camera, which including focusing step motor, driver power circuit, CCDfocal plane. According to the characteristics of CCD focal plane and the focusingprecision of mapping camera, three gear transmission mechanism was designed, andtransmission ratio was calculated in detailed. Accroding to the error theory, every partof focusing system was analyzed and calculated, including the focusing encodersensitivity, drive mechanism,error analysis. Focusing software was designed based onfunctional requirements for the focusing system software, research alogrithm oftraversing and climbing algorithm were introduced. It was verified that Coarsefocusing method and fine focusing method meet the precision requirement.Thefocusing stratedy suitable for three linear CCD mapping camera was proposed, andtwo contrasting focusing method for this focusing strategy were described in detail.4. The test results indicted that the focusing system designed for three line CCDmapping camera can meet the focusing technical requiements. The curve of focusingbased on various temperature was completed in the thermo-optical test. It verified thatthe focusing system could work in the thermal vacuum tank working conditions. Theposition curve of CCD focal plane MTF vs. temperature conditions was tested.whichwas the indicator and guiding role for three line CCD mapping camera for working inorbit更多还原