Abstract
The Hilbert-Huang Transform (HHT) is extended to the time series analysis of wave orbital velocities resulting from the superposition of waves propagating in different directions. On a theoretical basis, it is shown that an apparently chaotic velocity signal may result from the interaction of three or more waves, each one with its own period and direction of propagation. Such result is compatible with records of PUV instruments. The comparison between bivariate HHT with Fourier directional analysis shows several advantages of the former, such as identification of wave groups and non-linear interaction components.References
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