水面浮油膜光谱测量及光谱特征分析

Spectral measurement and characteristic analysis of an oil film floating above water

为深入解析水面浮油膜光谱特征,采用水面以上光谱测量方法,去除太阳直射和天空光两部分反射的影响,获取了珠江口水域不同厚度水面柴油膜光谱信息,对其光谱响应特征和机理进行了分析。结果表明：水面柴油膜光谱对背景水体光谱具有依赖性,但水面柴油膜光谱在可见光波段高于背景水体,且随着油膜厚度增加呈现不断增加的趋势;油膜反射光谱在蓝、紫光区域出现明显反射峰;360-500 nm区域油膜反射率与厚度相关系数大于0.8,有利于油膜厚度的遥感估算。最后指出,水面浮油膜类似于光学薄膜的单层增反膜,导致光谱反射率的增加,在360-420 nm区域的反射峰和石油类物质的荧光性有关。研究结果可为水域溢油污染遥感监测研究提供理论依据。

Spectral characteristics of oil films are essential for remote sensing technology to identify oil pollution on the surface of water. Therefore, we designed and performed a water-surface reflectance measurement for a diesel oil film with various thicknesses of diesel at the Pearl River Estuary. The response characteristics and mechanisms of the surface reflectance spectra of the diesel oil films were then analyzed. Results showed that the diesel oil films had spectral curves similar to that of water; however, the formers＇ reflectance spectra were higher than that of the latter. Moreover, a reflectance peak was observed in the blue and purple regions. Furthermore, wavelengths in the range of 360—500 nm can be taken as sensitive wavelengths because significant correlations between the thickness of the diesel oil film were obtained at these wavelengths. Therefore, from our result, we identify the diesel oil film as a single reflection-increased layer of a diaphragm, thus providing a higher spectral reflectance than water. Moreover, the reflectance peak in the in the 360—420 nm wavelengths channels was related to the fluorescence of petroleum substances. The results of this study provide a theoretical basis and technical support for monitoring oil pollution on the surface of water using remote sensing technology.