Feature extraction of dual-pol SAR imagery for sea ice image segmentation

Dual-polarization synthetic aperture radar (SAR) image data, such as that available from RADARSAT-2, provide additional information for discriminating sea ice types compared with single-polarization data. We performed a thorough investigation of published feature extraction and fusion techniques to make optimal use of this additional information for unsupervised sea ice image segmentation. Segmentation was performed by transforming the dual-pol data (i) into a new two-channel feature space (multivariate) and (ii) into a fused single-channel feature space (univariate). Both real and synthetic dual-polarization SAR sea ice images were transformed using a variety of methods and segmented using a recognized SAR segmentation algorithm (IRGS). The results indicated that the untransformed data provides consistent and high segmentation accuracy, avoids feature extraction pre-processing, and is thus recommended for SAR sea ice image segmentation using dual-pol imagery.