Compact Polarimetry for Oil Spill Characterization

RADARSAT Constellation Mission compact polarimetry data was acquired on July 25, 2020 over the bulk carrier MV Wakashio that ran aground off the coast of Mauritius, spilling 1000 tonnes of oil. Three CP discriminators, Degree of Linear Polarization (DLP), Degree of Polarization (DOP), and Entropy (H) were selected with the aim to investigate these parameters for oil spill characterization and the estimation of relative oil thickness. The discriminators were calculated for oil and oil-free areas and the results were consistent with the expected trend, which therefore suggested discrimination of oil and oil-free areas. An Area-based Classification-by-Histogram algorithm was developed and applied to the CP discriminators. There was a negative correlation between the oil and the ocean surface. In contrast, there was positive correlation between different areas within the oil spill, thus suggesting similar oil characteristics. The H image did, however, show some visual variability that may have been related to differences in the oil thickness.