This book discusses methods for measuring the water surface backscattering signature and estimating the near-surface wind vector over water using airborne radars, in addition to their standard application. Airborne FMCW demonstrator system, Doppler navigation system, airborne weather radar, airborne radar altimeter, and airborne precipitation radar are analyzed in order to be used for that purpose. The radars functionality is enhanced for their operation in a scatterometer mode. A circle flight and/or a rectilinear flight of an aircraft over the water surface is considered depending on the radar design features to perform measurements of the azimuth normalized radar cross section curve of the water surface and/or the near-surface wind speed and direction. Flight recommendations to perform measurements along with algorithms for measuring the water surface backscattering signature and for retrieval of the wind speed and direction over water are presented.