基于SAR后向散射的海上溢油检测研究

A Study on Oil Spill Identification Based on Backscattering of SAR Data

应用海面雷达后向散射系数检测海上溢油是目前海上溢油遥感监测的一个重要方向。本文以南海Envisat-ASAR数据为例,在分析SAR数据的基础上,应用Envisat-ASAR绝对定标计算方法,计算后向散射系数,研究应用SAR进行海上溢油遥感监测的散射特性,计算目标与海面边界后向散射系数梯度均值0σ与目标与海面后向散射系数均值差Δμ,并以两者结合作为区分海面油膜与自然现象的解译标志,从而为溢油识别提供依据。

Oil spill pollution has seriously impacted people＇s life,and occupies the first place according to the frequency,the distributed span and the harm degree.Therefore,how to solve the oil spill pollution effectively and scientifically has become an important issue,and how to carry on an accurate and quick detection of oil spill is the precondition to solve the oil spill pollution.Ocean backscattering is the research bases of passive microwave quantification.Using Envisat-ASAR data,this paper calculates the backscattering and analyzes the characteristics of oil spill and looks-likes backscattering,taking object and electromagnetic wave characteristics about ocean indexes,and figuring backscattering,thus,using △↓σ^0 as an index to distinguish oil spill and looks-alike.The hypothesis that ▽DN and Δμ etc.of dark patches in SAR images formed because of different reasons and will follow the Gaussian distribution with different expectations and variances,is proposed in this paper.By using this method it can erase some disturbs from ocean wave,and help identify the marine oil spill.