Affiliation: | 1. Centre national de la recherche scientifique (CNRS), institut de recherche sur les phénomènes hors equilibre (IRPHE), Marseille, France;2. The Johns Hopkins University, Applied Physics Laboratory, 11100 Johns Hopkins Road, Laurel, MD 20723-6099, USA;3. Département d''océanographie spatiale, IFREMER, centre de Brest, BP 70, 29280 Plouzané, France;4. NASA Goddard Space Flight Center, Laboratory for Hydrospheric Processes, Wallops Island, VA 23337, USA |
Abstract: | A generalization of the Woodward's theorem is applied to the case of random signals jointly modulated in amplitude and frequency. This yields the signal spectrum and a rather robust estimate of the bispectrum. Furthermore, higher order statistics that quantify the amount of energy in the signal due to nonlinearities, e.g., wave–wave interaction in the case of water waves, can be inferred. Considering laboratory wind generated water waves, comparisons between the presented generalization and more standard techniques allow to extract the spectral energy due to nonlinear wave–wave interactions. It is shown that our analysis extends the domain of standard spectral estimation techniques from narrow-band to broad-band processes. To cite this article: T. Elfouhaily et al., C. R. Mecanique 331 (2003). |