A method for the atmospheric correction of ENVISAT/MERIS data over land targets
A method for the atmospheric correction of ENVISAT/MERIS data over land targets
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DOI：
10.1080/01431160600815525
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发表时间：
2007-02-01
影响因子：
3.4
通讯作者：
Moreno, J.
中科院分区：
文献类型：
--
作者：
Guanter, L.;Gonzalez-Sanpedro, M. Del Carmen;Moreno, J.
已经实施了一种大气校正算法，用于从欧洲航天局（欧空局）环境卫星（ENVISAT）平台上的中分辨率成像光谱仪（MERIS）获得的图像中检索地表反射率。该算法的目的是估计校正所需的主要大气参数，气溶胶和水蒸气含量，从图像本身，导致在图像采集时的大气状态的最佳表征。一旦大气状态已被定义，第二步处理与检索的表面反射率，占地面海拔和粗糙度的贡献，以及大气相邻效应。本文的第一部分是致力于描述的方法，概述了在大气特征化的主要步骤，并在随后的表面反射率反演。第二部分详细介绍了验证任务。对AERONET不同站点的气溶胶光学厚度（AOT）和水汽含量与该方法的反演结果进行了比较。AOT在440、550和870 nm处的均方根误差（RMSE）分别为0.085、0.065和0.048。与现场测量结果的比较表明，除了撒哈拉沙尘入侵的事件，令人满意的性能。对于水蒸气，MERIS和AERONET结果之间的高度相关性被发现，虽然RMSE等于0.316克厘米22由于系统高估时，与AERONET数据相比。当将反演结果与欧空局的水蒸气水平2产品进行比较时，它下降到0.098。
An atmospheric correction algorithm for the retrieval of land surface reflectance from imagery acquired by the Medium Resolution Imaging Spectrometer (MERIS) on-board the European Space Agency (ESA) ENVIronmental SATellite (ENVISAT) platform has been implemented. The algorithm is designed to estimate the main atmospheric parameters needed in the correction, aerosol and water vapour contents, from the image itself, leading to an optimal characterization of the atmospheric state at the time of image acquisition. Once the atmospheric state has been defined, a second step deals with the retrieval of surface reflectance, accounting for the contribution of surface elevation and roughness as well as the atmospheric adjacency effect. The first part of this paper is devoted to the description of the method, outlining the main steps in the atmospheric characterization and in the subsequent surface reflectance retrieval. The validation task is detailed in the second part. Aerosol Optical Thickness (AOT) and water vapour content from different sites of the AErosol RObotic NETwork (AERONET) have been compared with the method's retrievals. Root Mean Square Errors (RMSEs) equal to 0.085, 0.065 and 0.048 are found for AOT at 440, 550 and 870 nm, respectively. Comparison with in situ measurements shows a satisfactory performance except for episodes of Saharan dust intrusions. For water vapour, a high correlation between MERIS and AERONET results is found, although the RMSE equals 0.316 g cm 22 due to a systematic overestimation when compared with AERONET data. It decreases to 0.098 when the retrievals are compared with the ESA water vapour level 2 product.