Segmentation of High-Frequency Radar–Measured Directional Wave Spectra Using the Voronoi Diagram

Abstract

Recent developments in the measurement of directional wave spectra using high-frequency (HF) radar have shown its ability to resolve multimodal wave spectra. Such spectra contain information about the different swell and wind?sea systems contributing to the ocean wave field. This paper presents the results of work to automatically segment multimodal wave spectra into the individual modes present. It describes how this is achieved by using sampled wave spectra and simple set theoretic transforms from mathematical morphology. By concentrating upon these simple transforms for regular sampling sets, the authors show that the same approach can be taken for wave spectra sampled with a nonuniformly distributed sampling set. This is particularly useful for spectra measured using HF radar since the inversion method used in their extraction yield spectra sampled onto a nonuniform sampling set. Results of this analysis are presented.