The equivalence of two radiometric methods relying on a single nadir-view optical sensor to determine the water-leaving radiance LW, namely the Single Depth Approach (SDA) and the Sky-Blocked Approach (SBA), was investigated applying identical hyperspectral radiometers operated on the same deployment platform. Values of LW from SDA and SBA measurements performed in the Black Sea across a variety of waters during ideal illumination conditions and with low-to-slight sea state, exhibited mean absolute differences within 0.5% in the blue-green spectral region and 2% in the red. This result, benefitting of a comprehensive parameterization of optical processes in combination with the characterization of sensors non-linearity, in-water response and reproducibility of absolute radiometric calibrations, indicated ample equivalence of the two near-surface methods in terms of performance and data reduction needs.

中文翻译：

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用等值的近地表法测定出水的辐射率。

使用相同的高光谱辐射计研究了两种依靠单个天底视图光学传感器确定出水辐射LW的辐射法的等效性，即单深度法（SDA）和天挡法（SBA）。相同的部署平台。在理想照明条件下和低至轻度海洋状态下，在黑海中跨各种水域进行的SDA和SBA测量得出的LW值，在蓝绿色光谱区域中的平均绝对差在0.5％以内，在2％处的平均绝对值在2％以内。这红色。这一结果受益于光学过程的全面参数化，以及传感器非线性，水响应和绝对辐射定标重现性的表征，