Title :
Study of Wave Group Velocity Estimation From Inhomogeneous Sea-Surface Image Sequences by Spatiotemporal Continuous Wavelet Transform
Author :
Chuang, Laurence Zsu-Hsin ; Li-Chung Wu
Author_Institution :
Coastal Ocean Monitoring Center, Nat. Cheng Kung Univ., Tainan, Taiwan
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.
Keywords :
image capture; image representation; image sequences; ocean waves; spatiotemporal phenomena; time-frequency analysis; wavelet transforms; FT method; Fourier transform; Morlet wavelet; STCWT; coastal areas; consecutive ocean wave images; diffraction; image processing; inhomogeneous sea-surface image sequences; ocean surface waves propagation; reflection; remotely captured wave image sequences; shoaling; spatiofrequency representation; spatiotemporal continuous wavelet transform; time-frequency representation; wave group velocity estimation; wave-field measurements; Continuous wavelet transforms; Image sequences; Spatiotemporal phenomena; Wavelet analysis; Wavelet domain; Inhomogeneous sea-surface image sequences; spatiotemporal continuous wavelet transform (STCWT); wave group velocity;
Journal_Title :
Oceanic Engineering, IEEE Journal of
DOI :
10.1109/JOE.2013.2269211