基于微波散射实验的油种识别研究

OIL TYPES IDENTIFICATION BASED ON MICROWAVE SCATTERING EXPERIMENT

海上溢油来源复杂,溢油种类多样,正确识别溢油类型对于溢油应急的快速反应具有重要意义。合成孔径雷达(synthetic aperture radar,SAR)具有全天时全天候的监测优势,在海面溢油监测中发挥着主力军作用,但在油种识别方面存在不足。利用C波段全极化散射计对柴油、原油、油水混合物和棕榈油进行外场实验观测,探究微波识别油膜的敏感特征参数,并将敏感特征参数应用于海上油膜实验获取的SAR图像进行油种识别。结果表明,在垂直(vertical transmission vertical reception,VV)极化方式下的油水差(?σ0)可以有效识别植物油和矿物油;基于d B和linear units表达的后向散射系数(NRCS)计算的抑制比(DR)在垂直(VV)和水平(horizontal transmission horizontal reception,HH)极化方式下可以有效识别植物油和矿物油,并且在交叉(vertical transmission horizontal reception/horizontal transmission vertical reception,VH/HV)极化方式下linear units表达的NRCS计算的抑制比可以识别原油和乳化油;极化差(PD)可用于识别原油、乳化油和植物油。

With complex sources and various types of oil spills at sea,correct identification of oil spill types is of great significance for the rapid response to oil spill incidents.Synthetic aperture radar(SAR)can perform all-day all-weather monitoring at sea surface for oil spill;however,there has been a deficiency in oil type identification.We applied the C-band full-polarization scatterometer in field experimental observations on diesel oil,crude oil,oil-water mixture,and palm oil to screen sensitive feature parameters for microwave identification of an oil film at sea,and the sensitive feature parameters were applied to the SAR images obtained from the offshore oil film experiments for oil-type identification.Results show that the oil-water difference(?σ0)in VV(vertical transmission vertical reception)polarization mode can effectively identify plant oil and mineral oil.The damping ratio(DR)calculated based on the normalized radar cross section(NRCS)expressed by dB and linear units,respectively,could effectively discriminate plant oil and mineral oil in VV and HH(horizontal transmission horizontal reception)polarization modes.In addition,in VH/HV(vertical transmission horizontal reception/horizontal transmission vertical reception)polarization mode,the damping ratio calculated by NRCS expressed by linear units could identify crude oil and emulsified oil,and using the polarization difference(PD),crude oil,emulsified oil,and plant oil could also be discriminated.