A feature extraction technique for synthetic aperture radar (SAR) sea ice imagery

A feature extraction technique is presented that extracts ice floes from synthetic aperture radar (SAR) sea ice imagery. The authors investigate two types of floe: 1) independent ice floes that collide and meet, and 2) component ice floes that melt and consolidate to form an independent ice floe. To detect independent ice floes, the authors consider two kinds of edges: 1) clear edges, and 2) blurred edges. They use a spatial enhancement technique combined with thresholding to obtain the clear edges. To detect the blurred edges, they make use of “corners” which are pixels where a considerable change in direction of a floe boundary occurs. To connect the corners appropriately, they incorporate both their geometric and semantic properties into heuristics that choose which pair of corners to connect. To investigate component ice floes, they have developed a technique that combines thresholding, correlation, morphological cleaning, and structural growing. The technique has been tested successfully on a large number of SAR images, including data from ERS-1