Simulation on the extraction of ships´ images embedded in speckle using cross-correlation of multilook SAR images and applications to Radarsat data

Preliminary results are reported on the simulation of ship detection and applications to Radarsat data using coherence images computed from cross-correlating multilook SAR images. The traditional techniques of ship detection by radars such as CFAR (Constant False Alarm Rate) rely on the amplitude data, and therefore the detection tends to become difficult when the amplitudes of ships images are at similar level as the mean amplitude of surrounding sea clutter. The proposed method utilizes the property that the multilook images of ships are correlated, while those of sea surface are covered by uncorrelated speckle. Thus, cross-correlation of multilook images yields the different degrees of coherence between the images of ships and water. The ability of the technique has been illustrated in the previous reports using Radarsat data, where the images of ships are clearly visible. In the present article, we examine the technique when the ships´ images are embedded in the surrounding sea clutter.