Speckle Suppression and Analysis for Polarimetric SAR Imagery

This paper addresses ship target detection in dual-frequency singlepolarization and fully polarimetric SAR data by using a global thresholding approach. The corresponding threshold values were determined from the gamma distribution (for single-polarization SAR data) and the chi-squared distribution (for fully polarimetric SAR data). Based on the experimental results, which were obtained from nine-look NASA/JPL AIRSAR POLSAR data, the complementary use of both the Cand L-band was found to remove ghost ships (due to azimuth ambiguity) and improve the resolution of ship targets. Moreover, it was observed that the use of fully polarimetric SAR information reduced undesired artifacts, which were particularly noticeable in the C-band single-polarization outputs. Index TermsPOLSAR, ship detection, global thresholding, statistical distribution, Wilks’ lambda