Method and apparatus for coherent marine radar measurements of properties of ocean waves and currents

摘要

A method and apparatus of determining a wave height directional spectrum of an ocean wave field using the intermediate-frequency (IF) signal from marine radars with a rotating antenna, using either a fully coherent or a standard non-coherent transmitter/receiver modified for coherent-on-receive use. The method may include receiving the IF radar ocean surface echo signal for a series of transmit pulses, at a sequence of azimuthal antenna positions, and a number of antenna rotations covering several minutes, then generating a matrix of complex IF signal samples from these, deriving phases for each sample, generating the difference in phase for consecutive azimuths, then Doppler shifts, and finally radial velocities. These are interpolated to a Cartesian-transformed representation cube of samples, a subset of which is Fourier transformed in three dimensions, filtered, and the resulting power spectrum generated is used to derive ocean wave height directional spectra, frequency spectra, and root-mean-squared wave height.