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 Feb 6;20(3):863. doi: 10.3390/s20030863.
This paper presents a model of upwelling radiation above the seawater surface in the event of a threat of dispersed oil. The Monte Carlo method was used to simulate a large number of solar photons in the water, eventually obtaining values of remote sensing reflectance (R). Analyses were performed for the optical properties of seawater characteristic for the Gulf of Gdańsk (southern Baltic Sea). The case of seawater contaminated by dispersed oil at a concentration of 10 ppm was also discussed for different wind speeds. Two types of oils with extremely different optical properties (refraction and absorption coefficients) were taken into account for consideration. The optical properties (absorption and scattering coefficients and angular light scattering distribution) of the oil-in-water dispersion system were determined using the Mie theory. The spectral index for oil detection in seawater for different wind conditions was determined based on the results obtained for reflectance at selected wavelengths in the range 412-676 nm. The determined spectral index for seawater free of oil achieves higher values for seawater contaminated by oil. The analysis of the values of the spectral indices calculated for 28 combinations of wavelengths was used to identify the most universal spectral index of R for 555 nm/440 nm for dispersed oil detection using any optical parameters.
本文提出了一种在存在分散油威胁的情况下海水表面上方上行辐射的模型。采用蒙特卡罗方法模拟水中大量太阳光子，最终获得遥感反射率（R）值。针对格但斯克湾（波罗的海南部）海水的光学特性进行了分析。还讨论了不同风速下浓度为10 ppm的分散油污染海水的情况。考虑了两种光学特性（折射和吸收系数）差异极大的油类。利用米氏理论确定了水包油分散体系的光学特性（吸收和散射系数以及角向光散射分布）。根据在412 - 676 nm范围内选定波长处反射率的结果，确定了不同风况下海水中油类检测的光谱指数。确定的无油海水光谱指数对于被油污染的海水具有更高的值。对28种波长组合计算得到的光谱指数值进行分析，以确定使用任何光学参数检测分散油时555 nm/440 nm的最通用R光谱指数。
