Nonstationary Analysis of the Directional Properties of Propagating Waves

Abstract

It is proposed that the sea surface be studied in a way that takes into account the observed groupiness of wind-generated waves. A new method of analysis to study the directional properties of the surface is developed. It is demonstrated that this method, based on wavelet transforms, allows the instantaneous wave propagation directions at various frequencies to be estimated. Furthermore, the approach is shown to yield wavenumber spectra directly–-a result of particular importance to such pursuits as remote sensing, gas transfer, and air-sea coupling.