青藏高原典型沙地地表反射率光谱特征与星地验证  

Spectral Characteristics of Typical Sandy Land Reflectance and Satellite Surface Product Validation in the Qinghai-Tibet Plateau

作　　者：刘勇[1,2] 许华 李莉 纪山 王博林 罗杰 李凯涛 郑杨 伽丽丽 江启峰 李正强 LIU Yong;XU Hua;LI Li;JI Shan;WANG Bo-lin;LUO Jie;LI Kai-tao;ZHENG Yang;QIE Li-li;JIANG Qi-feng;LI Zheng-qiang(School of Aeronautics and Astronautics,Xihua University Engineering Research Center of Intelligent Air-Ground Integration Vehicle and Control,Key Laboratory of Fluid and Power Machinery,Xihua University,Chengdu 610039,China;State Environmental Protection Key Laboratory of Satellite Remote Sensing&.State Key Laboratory of Remote Sensing Science,Aerospace Information Research Institute,Chinese Academy of Sciences,Beijing 100101,China;PLA 31002 Unit,Beijing100096,China;School of Aerospace Information,Space Engineering University,Beijing 101416,China)

机构地区：[1]西华大学航空航天学院智能空地融合载具及管控教育部工程研究中心,西华大学流体及动力机械教育部重点实验室,四川成都610039 [2]中国科学院空天信息创新研究院国家环境保护卫星遥感重点实验室,遥感科学国家重点实验室,北京100101 [3]31002部队,北京100096 [4]航天工程大学航天信息学院,北京101416

出　　处：《光谱学与光谱分析》2024年第11期3228-3235,共8页Spectroscopy and Spectral Analysis

基　　金：对外技术合作科研项目(E3KZ03010F);国家自然科学基金项目(42175146,42175148)资助。

摘　　要：测量地表反射率对研究地物光谱特征以及卫星地表产品检验具有重要意义。利用地物光谱仪获得青藏高原阿里地区的沙地地表反射率,并研究分析其典型光谱特征。针对Terra和Aqua卫星的中分辨率成像光谱仪(MODIS)的地表反射率产品(MOD09/MYD09)和地表反照率产品(MCD43 A4)开展真实性检验和误差影响分析。结果表明,阿里地区戈壁具有典型沙地光谱特征,各波段的地表反射率数值在0.08~0.35之间,在300~700 nm光谱范围的地表反射率随波长增大而增加,而在750~1750 nm光谱范围的地表反射率变化较小。与我国敦煌辐射校正场的沙地反射率相比,光谱曲线相似度很高,光谱夹角为2.18°。星地对比的结果受观测几何和大气光照条件的影响,下午星Aqua产品验证效果优于上午星Terra,平均误差约为5%,这与MODIS官方标称的精度相一致。研究表明,阿里地区沙地的光谱特征稳定且有代表性,是我国光学卫星在轨辐射定标和检验的理想场地。Measuring surface reflectance is crucial for studying the spectral characteristics of ground objects and inspecting satellite surface products.This paper uses a ground spectrometer to measure the sand surface reflectance in the Ali region of the Qinghai-Tibet Plateau,and studies and analyzes its typical spectral characteristics.Conduct authenticity testing and error impact analysis on the surface reflectance products(MOD09/MYD09)and surface albedo products(MCD43 A4)generated by the Moderate Resolution Imaging Spectroradiometer(MODIS)aboard the Terra and Aqua satellites.The results indicate that the Gobi in the Ngari region exhibits typical sand spectral characteristics.The surface reflectance values in each band range from 0.08 to 0.35.The surface reflectance in the 300~700 nm spectral range increases with the wavelength,while in the 750~1750 nm spectral range,the surface reflectance also increases with the wavelength.The surface reflectance changes less in the nm spectral range.Compared to my country's sand reflectance of the Dunhuang radiation correction field,the spectral curve is very similar,and the spectral angle is 2.18°.The observation geometry and atmospheric lighting conditions influence the results of the star-ground comparison.The validation accuracy of the afternoon star Aqua product is superior to that of the morning star Terra,with an average error of approximately 5%,aligning with the official nominal accuracy of MODIS.Research shows that the spectral characteristics of the sandy land in the Ngari area are stable and representative,making it an ideal site for on-orbit radiation calibration and inspection of our country's optical satellites.

关 键 词：地表反射率 沙地光谱 真实性检验 MODIS地表产品 

分 类 号：K11[历史地理—历史学]