The existing underwater topography SAR detection models did not consider polarization information of SAR.In this paper

the SAR polarization information is used for underwater topography detection

which is based on radar cross section（RCS） expression from Valenzuela

high frequency spectra expression of ocean waves and Polarization Whitening Filter（PWF）.Taiwan Shoal of China is taken as an example and its underwater topography is detected using single-polarization and full-polarization image of Radarsat-2.The results show that detection accuracy of full-polarization is better than that of single-polarization and illustrate that polarization information can effectively improve the accuracy of detection.