【作者】 赵发财；

【导师】 王淑荣；

【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， 2012， 博士

【摘要】 地球大气散射光中含有大气成分分布的重要信息，通过测量太阳直射的光谱辐照度和大气散射的光谱辐亮度，可以反演计算出大气中各种微量气体和气溶胶的含量，监测全球温室效应、臭氧层厚度变化和各种有害气体的排放等等。非偏振的太阳光经过大气层后，由于大气分子和气溶胶等的散射作用，散射光中电矢量垂直分量和平行分量的振幅发生变化，不再是各向同性的自然光，而成为部分偏振光或偏振光。空间紫外遥感仪器中通常含有光栅、反射镜等元件，由于这些元件对s光和p光的反射率或者透过率不同，因此对不同偏振光的响应度不同，为了准确测量大气辐亮度，必须对仪器的偏振响应进行校正。空间光学遥感仪器通常采用两种方法解决偏振问题：一是像OMI、SBUV/2等采用退偏器的方法；二是像GOME、SCIAMACHY等采用专门的偏振测试装置进行在轨测试修正。本论文开展了空间紫外遥感仪器偏振特性分析、紫外波段偏振测试方法、空间紫外遥感成像光谱仪器光学退偏和在轨偏振实时测量及修正等偏振响应校正方法研究。本文首先对紫外高光谱臭氧廓线探测仪的测量对象-地球大气紫外散射光波的偏振特性作了分析：包括大气分子的瑞利散射、气溶胶的大粒子Mie散射和它们之间的多次散射，并利用大气辐射传输软件库LibRadtran对不同情况下的大气辐亮度及其偏振作了模拟分析；并利用穆勒矩阵法推导了紫外遥感仪器的归一化偏振响应度公式，给出了偏振对辐射测量不确定度的计算公式，由模拟分析结果表明，控制遥感仪器的偏振响应小于0.01，偏振对辐射测量精度的影响满足目标要求。利用穆勒矩阵计算法给出了空间紫外遥感仪器的线性偏振响应理论计算公式；详细分析了引起空间紫外遥感仪器线性偏振响应的主要光学元件反射镜、衍射光栅的线性二次衰减；建立偏振实验测试测量系统，系统可实现250-500nm波段对单个元件及仪器整机的偏振响应测试，光学元件偏振响应测量值的不确定度约为1.5%，仪器整机偏振响应测量值的不确定度为1.6%。采用穆勒矩阵计算法分析了双光楔H-V型退偏器、双光楔旋光退偏器、改进LYOT型退偏器和双巴比涅型退偏器等空间光学遥感常用的光学退偏器的退偏原理，计算得到了它们相应的平均穆勒矩阵，并对其特点进行了分析；分别利用几何光学计算法、光学传递函数法和软件模拟分析法等方法对退偏器引入的像差进行了分析，确定对成像光谱系统像质影响；并对光学退偏器应用于空间紫外成像光谱仪进行了分析。针对紫外高光谱臭氧廓线探测仪结构特点，利用穆勒矩阵计算法对其偏振的主要来源扫描系统及大刻线密度平面反射光栅等偏振特性进行了详细分析，确定了仪器两种主要观测模式时的穆勒矩阵形式，确立了仪器偏振测量校正方案；对偏振响应校正因子的不确定度及校正方案进行数值模拟分析，模拟结果表明采用偏振测量/校正方案，偏振对大气辐亮度的测量精度影响小于2%，利用臭氧垂直探测仪完成了原理验证实验，结果表明方案精度满足要求，有效可行。更多还原

【Abstract】 The scattered sunlight contains essential information about the globaldistribution of atmospheric constituents, so the measurements of the spectralirradiance of the light from the sun and spectral radiance of the scattered light fromthe earth can provide information about a number of trace gases and aerosols tomonitor the global greenhouse effect, the change of ozone layer, gas pollution et al.Light reflected from the Earth’s atmosphere is linearly or partially linearly polarizedbecause of scattering of unpolarized sunlight by air molecules and aerosols. Thespace-borne ultraviolet spectrometers always contain optical components such asdiffraction gratings, mirrors whose reflectance or transmission are often polarizationdependent, so the instrument are normally sensitive to the state of polarization of light.In order to measure the radiance accurately, the polarization response of theinstrument must be eliminated from the polarization-sensitive measurement. Thespace-borne spectrometers have2options to treat the atmospheric polarization of theincoming light. Either the polarization information is destroyed by scrambling, as inthe OMI and SBUV/2instruments or the polarization of the incoming light has to bemeasured to correct for the polarization dependence of the instrument, as in theGOME and SCIAMACHY. The polarization characteristics of the space-borneultraviolet spectrometers, polarization measurements in the ultraviolet, the scramblingand measuring the polarization of incoming light methods are explored.In this dissertation the polarization characteristics of the scattered sunlight whichis the targeted object of ultraviolet hyperspectral ozone profile spectrometers(UHOPS)is analyzed, accounting for rayleigh scattering, mie scattering and multiple scattering.The radiance and polarization model calculations are performed using the LibRadtransoftware package. The radiometric measurement equation considering for polarizationis presented using mueller matrix calculus. The uncertainty in the on-orbit radiance measurement is presented, and the simulation results show that the measurementsuncertainty due to polarization is small for instruments with polarization responsesless than0.01.The linear polarization sensitivity of space-borne ultraviolet spectrometers ispresented using mueller matrix calculus. The diattenuation of the main portion of theinstruments (mirror and grating) is analyzed. A set of ultraviolet polarization testsystem is designed with250-500nm wavelength range to test optical components andinstruments. The uncertainty of optical components measurements is about1.5%, andof the optical instruments test is about1.6%.The double plate horizontal-vertical depolarizer, rotation depolarizer, improvedLyot depolarizer and the dual Babinet compensator depolarizer which are commonused in remote sensing are evaluated, and the spatial average of their Mueller matrixare gained. The depolarization properties of these depolarizers are described. Theaberrations of these depolarizers are analyzed using geometrical optics calculating,mtf and software simulation to evaluate the image degradation of imagingspectrometers.The polarization characteristics of the scan system and small groove spacinggrating that are the main sources of linear polarization sensitivity of UHOPS areanalyzed and the mueller matrix for the two main observations are gained. Accordingto polarization characteristics of UHOPS, the polarization correction algorithm ofinstruments is set. The uncertainty of polarization factor is presented and themathematical approach to obtain the polarization values from the instrumentobservations shows that the error on the measured radiance is within2%. The resultsof solar backscatter ultraviolet spectrometer experiment are within the specification ofmeasurement accuracy and the polarization correction algorithm satisfies therequirement.更多还原