Radar sea return and the radscat satellite anemometer

The latest information on the capillary portion of the ocean wave spectrum confirms the growth of such spectral components with wind speed to high values. The numerous radar return theories all seem to indicate that the radar acts as a "filter" that causes the signal to respond to ocean wave components near the "Bragg wavelength." Since these components are the ones that grow with wind speed, it is not surprising that observations of off-vertical radar backscatter indicate this growth in signal strength with wind speed. Analysis of NASA observations at 13.3 GHz and NRL observations at 8.9 GHz and 4.4 GHz demonstrate the strong response of the radar return at these frequencies to wind speed The RADSCAT concept of using a microwave radiometer to correct the radar signals for atmospheric attenuation in cloudy skies and to cross-check the radar when skies are clear is reviewed. Proposed experiments for SKYLAB flights during 1973 are discussed.