Shore-based GNSS-R method for marine oil spill detection

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 electromagnetic 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 increase 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 environment to a certain extent.