Baszanowska Emilia, Otremba Zbigniew, Piskozub Jacek
Department of Physics, Gdynia Maritime University, 81-225 Gdynia, Poland.
Institute of Oceanology, Polish Academy of Sciences, Powstańców Warszawy, 81-712 Sopot, Poland.
Sensors (Basel). 2020 Sep 18;20(18):5352. doi: 10.3390/s20185352.
This paper analyzes the digital modelling of radiance reflectance of the sea surface when the water column is polluted by oil-in-water emulsion. A method tracking the fate of two billion virtual solar photons was applied to obtain the angular distribution of bottom-up radiance for a plane of sunlight striking the sea surface. For the calculations, the inherent optical properties of seawater characteristic for the Gulf of Gdańsk (southern Baltic Sea) were used. The analyses were performed for two types of oils with extremely different optical properties for an oil concentration of 10 ppm and for a roughened sea surface with a wind speed of 2 m/s. The spectral index for oil detection in seawater for different viewing angles was determined based on the results obtained for reflectance at eight wavelengths in the range of 412-676 nm for viewing angle in the range from 80° to 0°, both on the side of incidence of direct sunlight and on the opposite side. The resulting calculated spectral indexes for different wavelength combinations indicated significant dependence on the viewing angle.
本文分析了水柱被水包油乳液污染时海面辐射反射率的数字建模。应用一种跟踪20亿个虚拟太阳光子轨迹的方法，来获取阳光照射海面平面的自下而上辐射的角分布。计算中使用了格但斯克湾（波罗的海南部）海水的固有光学特性。针对两种光学性质差异极大的油类，在油浓度为10 ppm且海面粗糙度为风速2 m/s的条件下进行了分析。基于在412 - 676 nm范围内八个波长、视角范围从80°到0°（包括阳光直射侧和对侧）的反射率计算结果，确定了不同视角下海水油类检测的光谱指数。不同波长组合得到的计算光谱指数表明其对视角有显著依赖性。
