Determination of space and time sea wave structure from frequency characteristics of the radio signal scattered by the sea

A method of determining sea-wave parameters from frequency characteristics of an RF signal scattered by the sea surface is considered. The method is based on the Doppler frequency shift due to orbital velocity of motion of long sea waves. It is shown that by measuring the frequency shift ofS-band signals scattered by a small (as compared to the sea-wave length) site on the sea surface, one is able to determine both integrated sea-wave parameters (e.g., rms waveheight and mean period) and the space-time structure of energy-carrying sea components. Results of field tests are presented substantiating the efficiency of the method and allowing measurement accuracy to be evaluated. The main systematic errors of the method are discussed.