Carrizo Carlos, Gilerson Alexander, Foster Robert, Golovin Andrii, El-Habashi Ahmed
Opt Express. 2019 Jan 21;27(2):1750-1768. doi: 10.1364/OE.27.001750.
A novel snapshot hyperspectral imager is introduced for ocean color (OC) applications and its capabilities are demonstrated. The instrument provides hyperspectral radiance images with a wide field-of-view (FOV) and short exposure time, which is valuable for the direct characterization of the wind-roughened surface in various illumination conditions and wind speeds. Uncertainties in the total(L), sky (L) and derived water-leaving (L)radiances at viewing angles of 20-60° are determined as a function of wind speed together with associated correlation coefficients and variances of the sea surface reflectance coefficient ρ. Estimated L uncertainties can partially explain the inaccuracy of satellite retrievals in the blue bands in the coastal waters. It is shown that in above-water measurements in no-glint conditions with viewing and azimuth angles of 40° and 90°, respectively, for both L(λ) and L(λ) the impact of FOV is minimal at least up to measured W = 5.7 m/s for full-angle FOV of 4° and larger. Implications of uncertainties for the derivation of water leaving radiance in above-water ship-borne and AERONET-OC measurements are discussed.
介绍了一种用于海洋水色（OC）应用的新型快照高光谱成像仪，并展示了其功能。该仪器可提供具有宽视场（FOV）和短曝光时间的高光谱辐射图像，这对于在各种光照条件和风速下直接表征风致粗糙表面非常有价值。确定了在20 - 60°视角下总辐射（L）、天空辐射（L）和导出的离水辐射（L）的不确定性与风速的函数关系，以及海面反射系数ρ的相关系数和方差。估计的L不确定性可以部分解释沿海水域蓝色波段卫星反演的不准确性。结果表明，在无镜面反射条件下的水上测量中，观测角和方位角分别为40°和90°时，对于L(λ)和L(λ)，至少在全角视场为4°及更大且测量风速W = 5.7 m/s时，视场的影响最小。讨论了不确定性对水上船载和AERONET - OC测量中离水辐射推导的影响。
