Analysis of directional ocean spectra as measured by H.F. radar

HF radar is becoming an important tool in the measurement and analysis of sea state. One reason for this is due to the high resolution of the measured directional spectra obtainable by inversion of the Doppler spectrum of the backscattered radar signal. Presented is an outline of the methods being employed to tackle the problem of recognizing the modes present in the directional spectra. This is necessary to assist in the identification of the “wind driven” spectral region, which will subsequently be used in the estimation of wind speed and direction. Presented also is an algorithm for extraction of modes from the spectra into sets of points forming regions of connected support. From which further modal analysis may be undertaken. The paper also discusses a technique based upon the generation of a Voronoi diagram to overcome problems associated with the preprocessing of spectral information derived from inversion of the Doppler spectra