Ocean surveillance with polarimetric SAR

A key mandate of the Canadian Department of National Defence (DND) is to provide surveillance over Canadian waters. Historically, this task has been executed using a combination of the Aurora CP-140 patrol flights and naval ship reports. Recently the use of commercial satellites, such as RADARSAT-1, has been explored foil ship detection applications. Future satellites, such as ENVISAT and RADARSAT-2 will have dual and/or quad-polarized SAR modes which potentially could provide information about a target's structure. It is anticipated that this additional information will improve ship detection capabilities using spaceborne imagery. We report the results for two polarimetric methods implemented here to evaluate their ship detection capabilities. Results using polarimetric methods indicate improved ship detection capabilities when compared to single channel results. One method provides structural information which is suitable for classification as shown in the results here. An extensive Target-to-Clutter Ratio study indicates that for ship detection applications, the HH and HV channels are more optimal for incidence angles > 45 degrees and < 45 degrees respectively. Instances where saturated signal data degrade the polarimetric detection rates are discussed.