A three‐dimensional analysis of marine radar images for the determination of ocean wave directionality and surface currents

Abstract

A series of spatial wave images recorded by a conventional marine radar is analyzed to determine the three‐dimensional E ( k x , k y , ω) spectrum. In the absence of a surface current the spectral energy in this three‐dimensional wave number frequency space will lie on a shell defined by the dispersion relationship. Any deviation from the expected dispersion relationship can be interpreted as being due to a current induced Doppler shift of the wave frequency. A least squares curve fitting technique is used to determine the surface current required to account for the observed Doppler shift. A comparison of the radar determined spectra and surface currents with ground truth data indicates that the radar system and analysis technique produces results consistent with conventional instrumentation.