Author(s): M. A. Arribas; J. J. Egozcue
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Keywords: No Keywords
Abstract: The Instantaneous Direction Method of describing directional ocean waves is presented. The starting point is that the time-series of surface elevation of the water contains more information than that used by the traditional, cross- spectral based, methods. The main concept is that of Instantaneous Direction. This direction is defined by horizontal projection of the normal vector to the surface but conveniently signed in order to indicate the sense of propagation of waves. These instantaneous directions are weighted in order to attain variance units. The distribution of Instantaneous Directions is proposed as a new and alternative directional descriptor. It can be easily estimated from the sample time series and the frequency distribution is readily obtained by band-pass filtering of the time-series. There are subtle differences between the Instantaneous Direction Distribution and the traditional Directional Wave Spectra but they are similar in practice. Some examples and comparisons are presented in order to validate the presented approach.
Year: 1991