Discriminating breaking in deep water waves

Records of deep water sea surface elevation alone, even when taken at high sampling rates, do not allow determination of which waves in the record are breaking. Although the white-capping and collapse of the front face of a breaking wave are clearly visible, they do not appear in any meaningful way in the output of an elevation gauge. Considerable research has been devoted to finding a method of detecting breaking events in a wave elevation record, but most of the models show little skill. Huang et al. [1992] suggested that an analytical method based on the Hilbert transform, which they called the Phase-Time Method, might have value. The present study evaluates the power of the Phase-Time method in detecting breaking wave in large scale laboratory experiments under a variety of deep water wave conditions. A useful model of deep water breaking wave detection is developed and its limits are stated.