FY-3F/HIRAS-Ⅱ的发射前光谱定标  

Pre-Launch Spectral Calibration of FY-3F/HIRAS-Ⅱ

作　　者：邵春沅 顾明剑[1] 漆成莉[2] 李路 杨天杭 陈星[1] Shao Chunyuan;Gu Mingjian;Qi Chengli;Li Lu;Yang Tianhang;Chen Xing(Key Laboratory of Infrared System Detection and Imaging Technology,Shanghai Institute of Technical Physics,Chinese Academy of Sciences,Shanghai 200083,China;National Satellite Meteorological Center,China Meteorogical Administration,Beijing 100081,China)

机构地区：[1]中国科学院上海技术物理研究所红外探测与成像技术重点实验室,上海200083 [2]中国气象局国家卫星气象中心,北京100081

出　　处：《光学学报》2024年第12期396-403,共8页Acta Optica Sinica

基　　金：国家重点研发计划(2022YFB3902901)。

摘　　要：基于仪器的光学视场特性进行有限视场和离轴效应的光谱模拟,研究针对面阵傅里叶光谱仪光谱校正的方法。首先,开展仪器线型函数(ILS)影响分析,确定不同影响因素(有限光程差、有限视场、离轴效应等)的分析方法;其次,以面阵型圆形探测器为例,结合仪器自身光学特性,构建仪器线型函数模型;然后,利用气体吸收光谱模拟离轴效应产生的光谱定标误差和光谱敏感性;最后,基于FY-3F/HIRAS-Ⅱ发射前光谱定标数据,进行光谱校正和定标精度验证。实验结果表明:有限视场和离轴效应使得光谱存在展宽,并向低波数方向偏移。经过光谱定标和校正,中心最差像元光谱定标精度由-24.69×10^(-6)减小到0.54×10^(-6),边缘最差像元由-513.38×10^(-6)减小到-0.15×10^(-6),且3个波段内所有像元均满足小于7×10^(-6)的指标要求。Objective The infrared Fourier spectrometer is based on interferometric spectroscopy,which features high spectral resolution and high sensitivity.Due to the ultra-fine spectral resolution of infrared hyperspectral atmospheric detection instruments,minor errors in spectral calibration can cause radiation measurement errors.High precision spectral calibration is an important prerequisite for quantitative inversion and the application of infrared remote sensing.The spectral calibration accuracy is affected by the limited field of view and off-axis effect.The traditional method is to obtain the spectral calibration coefficient by fitting multiple spectral lines.However,for issues such as ultra-high spectral resolution and wide observation spectral bands,most spaceborne infrared hyperspectral instruments employ forward modeling methods to build instrument spectral response models and remove various spectral effects.Methods Based on the optical field of view characteristics,we conduct spectral simulations of limited field of view and off-axis effect,and study spectral correction methods for the plane array Fourier spectrometer.Firstly,the influence of instrument line shape function(ILS)is analyzed to determine the analysis methods for different influencing factors(such as finite optical path difference,finite field of view,and off-axis effect).Next,by taking a planar circular detector as an example,the ILS function is constructed by combining the optical characteristics of the instrument itself.Then,the spectral calibration error and spectral sensitivity caused by the off-axis effect are simulated by gas absorption spectroscopy.Finally,test data of the optical field of view is obtained via slit scanning.Based on the pre-launch spectral calibration data of FY-3F/HIRAS-Ⅱ,spectral correction and calibration accuracy verification are carried out.Results and Discussions The experimental results indicate that the limited field of view and off-axis effect cause the spectrum to broaden and shift to a low wavenumber direction

关 键 词：光谱学 光谱定标 仪器线型函数 离轴效应 红外高光谱大气探测仪 

分 类 号：P412.27[天文地球—大气科学及气象学]