Atmospheric correction of ENVISAT/MERIS data over inland waters: Validation for European lakes
Atmospheric correction of ENVISAT/MERIS data over inland waters: Validation for European lakes
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DOI：
10.1016/j.rse.2009.10.004
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发表时间：
2010-03-15
影响因子：
13.5
通讯作者：
Moreno, Jose
中科院分区：
文献类型：
--
作者：
Guanter, Luis;Ruiz-Verdu, Antonio;Moreno, Jose
传统的水面气溶胶反演和大气改正方法都是基于近红外水反射率为零的假设。另一种在水上大气校正中变得非常流行的方法是通过大气和生物光学水模型的耦合反演来同时反演大气和水参数。这两种方法都可能在光学复杂的水体上造成重大误差，例如第11类水域，在这种水体中，水成分的浓度预计会有广泛的时间和空间变化。这使得水在近红外区的反射率是不可忽略的，并且水组分在极值下的水反射率响应不能用假设的生物光学模型来描述。作为这些方法的替代方法。本文介绍了SCAPE-M大气处理机，用于内陆水域ENVISAT/MERIS资料的大气自动改正。SCAPE-M通过对邻近陆地像元上的大气参数进行空间扩展来计算近陆地水像元的反射率，从而避免了对水组成及其光谱响应的先验假设。这一方法得到了SCAPE-M在一些欧洲内陆水域验证站的验证结果的支持，该工作给出了这一结果。在20个验证匹配中，将MERIS获得的气溶胶光学厚度、水反射率和水颜料与同时获得的MERIS图像的现场数据进行了比较。Sscape-M还与专为从MERIS数据中检索取水成分而设计的特定处理器进行了比较。讨论了SCAPE-M在一系列水类型下重现地面测量的性能，以及MERIS数据在SCAPE-M处理后使用半经验算法监测叶绿素a和藻蓝蛋白色素的能力。已经发现，SCAPE-M能够在浑浊水域上提供高精度的水反射，表现优于基于特定地点生物光学模型的模型，尽管在某些情况下，SCAPE-M在处理清澈水域方面也存在问题。(C)2009 Elsevier Inc.保留所有权利。
Traditional methods for aerosol retrieval and atmospheric correction of remote sensing data over water surfaces are based on the assumption of zero water reflectance in the near-infrared. Another type of approach which is becoming very popular in atmospheric correction over water is based on the simultaneous retrieval of atmospheric and water parameters through the inversion of coupled atmospheric and bio-optical water models. Both types of approaches may lead to substantial errors over optically-complex water bodies, such as case 11 waters, in which a wide range of temporal and spatial variations in the concentration of water constituents is expected. This causes the water reflectance in the near-infrared to be non-negligible, and that the water reflectance response under extreme values of the water constituents cannot be described by the assumed bio-optical models. As an alternative to these methods. the SCAPE-M atmospheric processor is proposed in this paper for the automatic atmospheric correction of ENVISAT/MERIS data over inland waters. A-priori assumptions on the water composition and its spectral response are avoided by SCAPE-M by calculating reflectance of close-to-land water pixels through spatial extension of atmospheric parameters derived over neighboring land pixels. This approach is supported by the results obtained from the validation of SCAPE-M over a number of European inland water validation sites which is presented in this work. MERIS-derived aerosol optical thickness, water reflectance and water pigments are compared to in-situ data acquired concurrently to MERIS images in 20 validation match-ups. SCAPE-M has also been compared to specific processors designed for the retrieval of take water constituents from MERIS data. The performance of SCAPE-M to reproduce ground-based measurements under a range of water types and the ability of MERIS data to monitor chlorophyll-a and phycocyanin pigments using semiempirical algorithms after SCAPE-M processing are discussed. It has been found that SCAPE-M is able to provide high accurate water reflectance over turbid waters, outperforming models based on site-specific bio-optical models, although problems of SCAPE-M to cope with clear waters in some cases have also been identified. (C) 2009 Elsevier Inc. All rights reserved.