岸基GNSS-R海上溢油探测方法

摘要

From the perspective of shore-based application, a marine oil spill detection model based on the inversion of the target water's relative dielectric constant was established using the three-antenna global navigation satellite system-reflection(GNSS-R)technology,the partial depolarization phenomenon of the elec-tromagnetic wave, and the mapping relationship between reflectivity and characteristic function of surface roughness.For this purpose,GNSS direct signal,left-hand and right-hand circular polarization components of reflected signals were collected by two field experiments for heavy oil and intertidal zone respectively.After processing the data according to the inversion model, the summary as well as the analysis were carried out. From the experimental results,the mean of retrieved dielectric constant of the oil covered surface is 2.14,its standard deviation is 1.44, and the dielectric constant of the beach has undergone a process of obvious in-crease and decrease,which is highly consistent with the flood and ebb tide alternates.The difference between oil and water inversion is obvious.The inversion results have a good agreement with the theoretical dielectric constant,which means that this method is feasible for marine oil spill remote sensing in shore-based environ-ment to a certain extent.%从岸基角度出发,利用全球导航卫星系统反射信号(GNSS-R)技术,同时结合电磁波的部分去极化现象以及反射率与海面粗糙度特征函数的映射关系,建立了三天线观测模式下的海上溢油探测模型,根据反演出目标水域的相对介电常数来判断有无溢油.通过2次实验分别采集污油和潮间带的GNSS直射信号以及反射信号中的左旋、右旋圆极化分量,依据反演模型处理数据并进行了总结与分析.从实验结果来看,当探测表面为油面时反演出的相对介电常数其均值为2.14,标准差为1.44,而海滩在历经潮水的涨落时所反演出相对介电常数值也存在明显的由小增大再减小的过程,油、水反演值差异明显,同时与理论相对介电常数值具有较好的一致性,说明此方法在岸基海上溢油遥感领域具有一定的可行性.