SAR Measurement of Ocean Surface Wind Using A Physics Model

Results of ocean surface wind speed retrieval from C-band ENVISAT ASAR images using a physics wind model are shown. The physics model is based on the radar backscatter theory in which the radar cross section is calculated considering the contribution of both Bragg scattering or resonance and specular reflection from the sea surface. The wind speeds retrieved from VV- or HH-polarized ASAR images using the physics model were compared to both buoy measurements in Hong Kong coastal waters and that retrieved using the empirical C-band algorithms (CMOD4, CMOD5, CMOD_IRR2). The results show the feasibility of the physics model for ocean surface wind speed retrieval from both VV and HH-polarized ASAR images at moderate wind condition.