A Multipolarization Analysis of Coastline Extraction Using X-Band COSMO-SkyMed SAR Data

In this study, COSMO-SkyMed (CSK) Synthetic Aperture Radar (SAR) data, collected by the single-polarization stripmap Himage mode, are exploited for coastline extraction purposes. First, a multipolarization analysis of sea surface back-scattering is undertaken using the Improved Integral Equation Method (IIEM). Then, a simple two-step approach is proposed to extract the continuous coastline from co- and cross-polarized Himage CSK SAR data. The approach is framed into two steps: 1) obtaining a binary output from the SAR image using a global threshold Constant False Alarm Rate (CFAR) detector; and 2) extracting the continuous one-pixel coastline from the binary output with a conventional Sobel edge detector. The proposed approach is verified against actual CSK SAR data and it is shown to be both effective and accurate when low-to-moderate wind conditions apply.