The quasi-specular model and a two-scale model are used to extract the wind speed from essentially exact numerical calculations of the average radar cross section of one-dimensional surfaces with ocean-like height spectra. These surfaces contain variations in their height on spatial scales which are smaller than the incident electromagnetic wavelength. It is shown that using the quasi-specular model, good wind speed estimates can be obtained if the quasi-specular model is modified to use only a portion of the surface spectrum below some cutoff value. However, the wind speed estimates are highly sensitive to this cutoff, and the optimal value depends on the polarization, electromagnetic wavelength, and wind speed. For the two-scale model, wind speed estimates tend to be slightly low, but in all cases examined herein the exact wind speed was within or very near the 95% confidence limits of the estimated value. Wind speed estimates are also generally observed to be slightly better at an electromagnetic wavelength of 30 cm than at 3 cm. It is also shown that when the so-called separation wavenumber varies between roughly k0/2.5 and k0/6.0, it has little effect on the wind speed estimates. ¿ 1998 American Geophysical Union |