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Wavelet Coherence over Submerged Breakwaters

Author(s): Zeris Athanasios; Prinos Panayotis

Linked Author(s): Panagiotis Prinos

Keywords: Waves breakwaters interaction; Wavelets; Wavelet coherence

Abstract: In the present article, wavelet cospectrum and wavelet coherence analysis is applied for water wave variables above submerged breakwaters. Laboratory surface elevation data are transformed into the wavelet domain for the case of breakwater of rubble-mound type. Image processing techniques were applied on video sequences for the extraction of the surface elevation. Traditional edge detection algorithms and algorithms based on the image wavelet transformation are implemented with the appropriate thresholds for the surface profile extraction. The Morlet wavelet is used for the free surface representation both in the time and frequency domains. Statistical significance and the edge effects of the transformation are incorporated in the mathematical procedure. The Cross Wavelet Transform and the Cross Wavelet Power are taking into account for two time series of the surface variation. The Wavelet Coherence representation for two time series simultaneously acquired is given with the appropriate smoothing operator in order the above quantity to have meaningful values for the regions in the joint time frequency domain with co varying behaviour.


Year: 2007

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