Sea Oil Slick Observation Using Hybrid-Polarity SAR Architecture

In this study, hybrid-polarity (HP) architecture is exploited to observe sea oil slicks. HP features are interpreted in terms of sea surface scattering with or without oil slicks, under low-to-moderate wind conditions. They are shown to exhibit a different sensitivity with respect to slick-free, weak-damping slick-covered, and oil-covered sea surfaces. This sensitivity is verified against HP measurements obtained transforming actual L- and C-band quad-polarimetric synthetic aperture radar (SAR) data where both oil slicks and weak-damping look-alikes are present. Experiments demonstrate: 1) the remarkable performance of HP features to both observe oil slicks and distinguishing them from weak-damping look-alikes; 2) the marginal effect played by the sensor´s noise floor on HP features performance; 3) the pronounced sensitivity of the HP features to the damping properties of the surfactants; and 4) the comparable performance that characterizes polarimetric entropy derived by HP and conventional polarimetric measurements.