利用热红外遥感技术探测海面溢油存在能够全天时探测、 更好地探测海表及油膜辐射特征和对油膜厚度的识别潜力较大等优势。 而热红外发射率是物体在指定温度时的辐射能与同温度黑体辐射能的比值, 在常温范围内, 物体的发射率光谱与温度无关, 仅与材质属性及波长相关。 基于这一假设, 以山东省东营市胜利油田孤岛采油厂获取的原油样品与渤海湾海水为材料, 利用102F傅里叶变换热红外光谱辐射仪设计海面油膜发射率光谱实验, 系统的测量分析了海面油膜随厚度连续变化过程中海面油膜发射率的变化特征与产生机理。 结果表明, 海表油膜的热红外发射率在甚薄阶段(20~120 μm)变化较大, 利用热红外发射率光谱能够较好的探测海表甚薄油膜; 在8~10 μm和在13.2~14 μm波段范围内, 海水与厚度为20 μm的甚薄油膜存在较为稳定的发射率差异, 利用该光谱范围内的油膜发射率可以用来探测20 μm的甚薄油膜; 在11.7~14 μm波段范围内, 油膜发射率与其厚度相关性小, 油膜的发射率明显低于本底海水的发射率, 利用该光谱范围内的油膜发射率可以用来探测较薄油膜的有无; 在11.72, 12.2, 12.55, 13.48和13.8 μm这几个波长附近, 油膜发射率随着油膜厚度的增加呈现出递增或递减, 且变化幅度较大, 利用这几个波长附近谱段的发射率可以用来探测较薄油膜的发射率光谱响应。

Detecting oil slick covered seawater surface using the thermal infrared remote sensing technology exists the advantages such as: oil spill detection with thermal infrared spectrum can be performed in the nighttime which is superior to visible spectrum, the thermal infrared spectrum is superior to detect the radiation characteristics of both the oil slick and the seawater compared to the mid-wavelength infrared spectrum and which have great potential to detect the oil slick thickness. And the emissivity is the ratio of the radiation of an object at a given temperature in normal range of the temperature (260~320 K) and the blackbody radiation under the same temperature., the emissivity of an object is unrelated to the temperature, but only is dependent with the wavelength and material properties. Using the seawater taken from Bohai Bay and crude oil taken from Gudao oil production plant of Shengli Oilfield in Dongying city of Shandong Province, an experiment was designed to study the characteristics and mechanism of thermal infrared emissivity spectrum of artificial crude oil slick covered seawater surface with its thickness. During the experiment, crude oil was continuously dropped into the seawater to generate artificial oil slick with different thicknesses. By adding each drop of crude oil, we measured thereflectivity of the oil slick in the thermal infrared spectrum with the Fourier transform infrared spectrometer (102F) and then calculated its thermal infrared emissivity. The results show that the thermal infrared emissivity of oil slick changes significantly with its thickness when oil slick is relatively thin (20~120 μm), which provides an effective means for detecting the existence of offshore thin oil slick. In the spectrum ranges from 8 to 10 μm and from 13.2 to 14 μm, there is a steady emissivity difference between the seawater and thin oil slickwith thickness of 20 μm. The emissivity of oil slick changes marginally with oil slick thickness and clearly below that of seawater in the spectrum range from 11.7 to 14 μm, this spectrum range can be practically used to distinguish oil slick from seawater; Around the wavelength of 11.72, 12.2, 12.55, 13.48 and 13.8 μm, the emissivity of oil slick presents clearly increasing or decreasing trends with the increase of its thickness, which are one of the best wavelengths for observing the offshore oil slick and estimating its thickness.