Cross-Correlation Between Polarization Channels in SAR Imagery Over Oceanographic Features

This letter discusses cross-correlation features derived from near-coincident RADARSAT-2 quad-polarimetric and RISAT-1 hybrid-polarity (HP) measurements collected during the NOrwegian Radar oil Spill Experiment in 2015 (NORSE2015). We show that the imaginary part of the cross-correlation between RH and RV is an HP parallel to the real part of the cross-correlation between HH and VV earlier proposed for oil spill characterization. We compared the RADARSAT-2 and RISAT-1 scenes, separated in time by less than an hour, and the results show a clear difference between the slicks across these acquisitions. The development of the oil spills was closely monitored during NORSE2015. Due to the evolving nature of the oil spills and the weathering processes acting upon the spills, our results also indicate an importance of a high synthetic aperture radar sampling rate during an actual oil spill event.