漂浮透明油品的紫外反射光谱特性研究

石油产品的庞大运输量增加了重大污染事故的风险，给生态安全带来了巨大威胁。其泄漏事故往往具有突发性、偶然性以及污染范围大等特点，传统的化学采样检测并不适用于现场的应急监测和定量预警。卫星遥感以及机载成像的发展为事故的检测提供了有效手段，但因为水面漂浮油品颜色特征不明显，多呈透明色，RGB相机下水和水面漂浮油品难以区分，严重影响成像监测效果。尝试从水与油品的光谱反射率特性的差异出发，寻找油品的特征波段，提高图像中水与油的对比度，以实现溢油监测。针对漂浮油品的光谱测量，已有研究选用的实验容器与环境条件与自然水体中的综合光学特征存在明显差异，难以为现场泄漏事故的监测提供相应的数据支持。为模拟实际的泄漏情景，在人工开阔湖面上使用地物光谱仪对汽油和二甲苯两类透明油品及类油化学品进行紫外可见反射光谱特性的测量探究。光谱测量结果显示，样品与水在各波段区间的光谱角余弦值均接近1，但光谱反射率差值在紫外波段明显大于其他波段，说明漂浮汽油与二甲苯这类透明油品与湖水的光谱反射率曲线形状差异基本一致，而幅值差异在紫外波段处最大。为进一步论证光谱特征分析结果，选择365，436，546以及700 nm四个紫外-可见波段的滤光片，对样品进行成像分析。成像分析结果显示，汽油与二甲苯两种漂浮透明油品与湖水在紫外波段处的图像总体灰度对比值与纹理特征差距明显高于其他可见光波段。因此，选用紫外波段进行水面漂浮油品的成像监测能有效提高油品与自然水面的成像对比度。该实验在自然光与湖面自然水体的条件下进行，极大程度地模拟了实际的透明油品泄漏污染情景，为透明油品及类油化学品机载遥感监测的波段优选提供了理论与数据支持。

Research on UV Reflective Spectrum of Floating Transparent Oil

The increasing amount of petroleum products has increased the risk of the pollution accidents, which could pose an acute threat to ecological safety. The leakage accidents often have the characteristics of suddenness, contingency and large pollution. The traditional chemical sampling detection method is not suitable for on-site emergency monitoring and quantitative warning. The development of satellite remote sensing and airborne imaging technology provides effective methods for the detection of accidents. However, the color characteristics of the floating transparent oil product are not obvious, and it seriously affects the imaging monitoring effect and poses a great threat to ecological security. According to the difference of the spectral reflectance characteristics of the water surface and the oil product, selecting a suitable operating band to improve the imaging effect is a common method for oil spill monitoring. For the spectral measurement of floating oil products, the existing researches were often carried out in the experimental containers, which have different optical characteristics in natural water. It is difficult to provide corresponding data support for the monitoring of on-site leakage accidents. In order to simulate the actual leakage scene, UV-Visible spectroscopic characteristics of transparent oils such as gasoline and xylene were investigated on the surface of artificial lake in this paper. Spectral measurement results show that the spectral angle cosine of the sample and water in each band interval is close to 1, but the spectral reflectance difference is significantly larger than the other band in the ultraviolet band, indicating the spectral characteristics of transparent oil were similar to the lake water in shape, but there is the largest difference in amplitude in the ultraviolet wavelength. To further demonstrate the results of spectral feature analysis, four ultraviolet-visible band filters of 365, 436, 546 and 700 nm were selected for imaging verification. The results show that the difference between the spectral reflectance curve of transparent oils such as floating gasoline and xylene and the amplitude of lake water is the largest at the ultraviolet wavelength, and the overall grayscale contrast of the two floating transparent oils and lake water at the ultraviolet wavelength is made. The difference between value and texture features is significantly higher than that in other visible wavelengths. Therefore, the use of the ultraviolet wavelength for imaging monitoring of floating oil products can effectively improve the imaging contrast between oil and natural water surface. The experiments were carried out under the conditions of natural light and natural water on the lake surface, which greatly simulated the actual transparent oil spill pollution scenarios and provided the most representative theoretical and data support for transparent oil imaging band optimization for airborne remote sensing monitoring.