Study of Wave Group Velocity Estimation From Inhomogeneous Sea-Surface Image Sequences by Spatiotemporal Continuous Wavelet Transform

Abstract

In this paper, a new image processing technique is introduced for the analysis of consecutive ocean wave images by spatiotemporal continuous wavelet transform (STCWT) using the Morlet wavelet as the mother wavelet. This technique, which has been adapted to give a full time–frequency and spatiofrequency representation of ocean surface waves from remotely captured wave image sequences, provides more detailed information from wave-field measurements than the traditional Fourier transform (FT) method. A series of numerical simulations of wave image sequences was analyzed to justify the algorithm and to present quantitative theoretical results on the propagation of ocean waves for normal incidence, diffraction, reflection, and shoaling in coastal areas. The comparisons of these estimates to simulated conditions for several wave parameters show that the wavelet theory is applicable to the identification of wave spectra from inhomogeneous sea-surface image sequences.