Abstract Many coastal waters include large areas of Optically Shallow Waters (OSWs) where the sea-bottom affects above-water observations of remote sensing reflectance (Rrs [sr−1]). If not treated, the effect of bottom reflectance will interfere with the correct retrieval of Water Constituent Concentrations (WCCs) from hyperspectral and multispectral remote sensing observations. To study this phenomenon in more detail, the existing semi-infinite 2SeaColour Radiative Transfer (RT) model was modified into a finite water layer model, bounded by a diffusely reflecting surface at the sea-bottom. From simulations with the new model, called Water - Sea Bottom (WSB) model, it was observed that a ratio of spectral bands in the Near-Infrared, bands 750 nm and 900 nm, is nearly insensitive to the WCCs and increases with the shallowness of the water, and therefore can be used as a robust index to detect OSWs. The newly established Near-Infrared Bottom Effect Index (NIBEI) was applied to a series of satellite observations over the Wadden Sea during high and low tidal phases. Images from the MEdium Resolution Imaging Spectrometer (MERIS) and the Ocean and Land Colour Instrument (OLCI) were processed to retrieve WCCs of the study area. The results indicate that the sea-bottom effect in OSWs affects the accuracy of atmospheric correction and retrievals. On the other hand, applying the NIBEI to flag OSWs improves the reliability and consistency of WCCs maps. The application of proposed NIBEI on satellite images requires only Top Of Atmosphere (TOA) radiances at 750 nm and 900 nm and does not depend on atmospheric correction and ancillary local input data (e.g., bathymetry map, bottom type, empirical coefficients, in-situ measurements). As a result, the proposed NIBEI can readily be applied to detect OSWs on various ocean colour remote sensors in various shallow coastal regions.

中文翻译：

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海底效应对辐射传输模型支持的浅潮水中 MERIS 和 OLCI 图像中水成分浓度反演的影响

摘要 许多沿海水域包括大面积的光学浅水区 (OSW)，其中海底影响遥感反射率 (Rrs [sr-1]) 的水上观测。如果不加以处理，底部反射率的影响将干扰从高光谱和多光谱遥感观测中正确检索水成分浓度 (WCC)。为了更详细地研究这种现象，现有的半无限 2SeaColour Ra​​diative Transfer (RT) 模型被修改为有限水层模型，以海底漫反射面为边界。从使用称为水 - 海底 (WSB) 模型的新模型进行的模拟中，观察到近红外波段 750 nm 和 900 nm 波段的比率对 WCC 几乎不敏感，并且随着浅度的增加而增加的水，因此可以用作检测 OSW 的稳健指标。新建立的近红外海底效应指数 (NIBEI) 被应用于在高潮和低潮阶段对瓦登海的一系列卫星观测。处理来自中分辨率成像光谱仪 (MERIS) 和海洋和陆地颜色仪器 (OLCI) 的图像以检索研究区域的 WCC。结果表明，OSW中的海底效应会影响大气校正和反演的准确性。另一方面，应用NIBEI 标记OSW 提高了WCC 地图的可靠性和一致性。提议的 NIBEI 在卫星图像上的应用只需要 750 nm 和 900 nm 的大气顶部 (TOA) 辐射，并且不依赖于大气校正和辅助的本地输入数据（例如，测深图、底部类型、经验系数，原位测量）。因此，所提出的 NIBEI 可以很容易地应用于检测各种浅海沿海地区各种海洋颜色遥感器上的 OSW。