Radar backscatter from a wind roughened water surface in the Bragg regime

Measurements of the normalized radar cross section (σ^o ) made by the YSCAT ultra-wideband scatterometer during an extended deployment at Lake Ontario are analyzed and compared with anemometer wind measurements to study the sensitivity of σ^o to the wind speed as a function of the Bragg wavelength. Wind speeds from 4.5 m/s to 12 m/s are studied at frequencies of 2 to 14 GHz and incidence angles within the Bragg regime, 30° to 50°. Adopting a power law model to describe the relationship between σ ^o and wind speed, the wind speed exponents and upwind/downwind (u/d) ratios of σ^o are presented as a function of the ocean Bragg wavelength. Analysis of the wind speed dependence of the normalized measurement variance suggests that Bragg scattering does not explain the observed scattering characteristics