On Airborne Doppler Navigation System Application for Measurement of the Water Surface Backscattering Signature and Estimation of the Near-Surface Wind

ABSTRACT

A method for measuring the water surface backscattering signature and estimating the near-surface wind vector over water using the airborne Doppler navigation system in addition to its standard navigational application is discussed. A case of an airplane circle flight measurement of the azimuth normalized radar cross section curve of the water surface in the range of middle incidence angles is considered. The system operates in the scatterometer mode and uses a fore-beam directed to the right side at a typical mounting angle in the vertical plane that is not so far from nadir at a straight flight. Wind vector is recovered from the azimuth normalized radar cross section curve obtained. Algorithms for measuring the water surface backscattering signature and extracting the wind speed and direction are proposed.