SAR Polarimetry for Effective Sea Oil Slick Observation

In the context of sea oil slick observation, satellite Synthetic Aperture Radar (SAR) is the most effective remote sensing tool to observe illegal oil spills, support remediation activities and to monitor offshore critical infrastructures as oil fields. Nowadays, the availability of a virtual constellation of polarimetric SARs characterized by multi-polarization, multi-frequency and multi-imaging capabilities offers the unique opportunity to exploit an unprecedented amount of information for sea oil slick observation purposes. In this study, among the different polarimetric features that allow: i) detecting sea oil slicks, ii) discriminating strong- from weak-damping surfactants and iii) providing a spatial zoning of the damping properties of a given surfactant, the standard deviation of the co-polarized phase difference (CPD) is considered. Experimental results, undertaken over a wide dataset of actual SAR imagery collected at different imaging modes (frequency, incidence angle, noise floor, polarization) under different environmental conditions (sea state, type of oil), showed that the standard deviation of the CPD is a reliable and robust polarimetric parameter to perform effective sea oil slick monitoring.