结合NCEP再分析资料优化的6S模式大气校正方法  

Optimized 6S Model Atmospheric Correction Method Combined with NCEP Reanalysis Data

作　　者：王雪丹 王玉峰[1] 刘凯[1] 彭志青 刘晶晶[1] 狄慧鸽[1] 宋跃辉[1] 华灯鑫[1] Wang Xuedan;Wang Yufeng;Liu Kai;Peng Zhiqing;Liu Jingjing;Di Huige;Song Yuehui;Hua Dengxin(Laser Radar Center of Remote Sensing of Atmosphere,School of Mechanical and Instrument Engineering,Xi an University of Technology,Xi'an 710048,Shaanxi,China)

机构地区：[1]西安理工大学机械与精密仪器工程学院激光雷达大气遥感研究中心,陕西西安710048

出　　处：《光学学报》2024年第6期79-91,共13页Acta Optica Sinica

基　　金：国家自然科学基金(U1733202);陕西省创新能力支撑计划(2020-TD014);陕西省农业科技创新驱动项目(NYKJ-2022-XA-011)。

摘　　要：以我国高光谱遥感卫星——环境1号卫星为例,开展结合NCEP再分析资料辅助优化的6S大气校正方法的分析。首先,考虑到高光谱图像缺少标准反射率产品的问题,利用最优化估计方法构建高光谱反射率曲线,并作为标准曲线,用于大气校正结果的验证。其次,基于6S大气校正理论,开展了大气校正的敏感性分析,确定了气溶胶光学厚度的敏感因素以及气溶胶类型、大气模式和大气温湿度对大气校正系数的敏感性。在此基础上,提出了NCEP再分析资料辅助优化的6S大气校正方法,利用NCEP再分析资料提供的大气温湿度廓线、水平能见度反演的550 nm气溶胶光学厚度等数据资料,优化6S模式的输入参数,得到准确的大气校正系数X_(a)、X_(b)和X_(c),获得大气校正后的不同地物反射光谱曲线。最后,选取西安作为试验区,以水体为例,进行波谱曲线对比,利用标准曲线对校正结果进行精度评价。对比分析结果表明,NCEP再分析资料辅助优化的6S模式校正的地面反射率结果明显优于6S的大气校正结果,与标准曲线具有一致的反射率变化趋势,二者的相关系数达到0.8596,标准差低于0.0685,各波段地面反射率逐像元误差的平均值和标准差接近0.02,反映了利用NCEP辅助数据优化的6S模式对大气校正有着明显的改善作用,可提高6S大气校正的地物反射率反演精度。Objective Unlike panchromatic and multispectral images,hyperspectral images have a high spectral resolution that causes more difficult atmospheric correction.Additionally,the atmospheric correction methods and correction accuracy based on the 6S model have been catching attention.China has launched several hyperspectral imaging sensor payloads,such as Environment 1 satellite,Gaofen 5,and resource satellites.Meanwhile,these satellites play an increasingly important position in agricultural remote sensing,forestry remote sensing,environmental monitoring and other fields,and the atmospheric correction technology for these hyperspectral remote sensing satellites is constantly developing.Taking China s hyperspectral remote sensing satellite Environment 1 satellite as an example,we carry out an optimized 6S atmospheric correction method combined with NCEP reanalysis data to improve 6S atmospheric correction accuracy.Methods First,considering the lack of standard reflectance products for hyperspectral images,the hyperspectral reflectance curve is constructed by the optimization estimation method and is regarded as the standard curve to verify the atmospheric correction results.Secondly,based on 6S atmospheric correction theory,we carry out sensitivity analysis and determine the most sensitive factors of aerosol optical thickness and the sensitivity of the aerosol model,atmospheric model,and atmospheric temperature and humidity to atmospheric correction coefficient.On this basis,an optimized 6S atmospheric correction method combined with NCEP reanalysis data is proposed.The aerosol optical thickness at 550 nm,atmospheric temperature and humidity profiles,and other data provided by NCEP are adopted to optimize the input parameters of the 6S model.Meanwhile,accurate atmospheric correction coefficients Xa,Xb,and Xc can be obtained,and the reflectance spectral curves of different ground objects are thus obtained after optimized atmospheric correction.Finally,by choosing Xi'an as the test area,the spectral curve of the water

关 键 词：大气光学 高光谱图像 大气校正 6S 气溶胶 NCEP 

分 类 号：O436[机械工程—光学工程]