| Autor: |
Ridgway, Jeffrey, Larsen, Michael L., Waldman, Cye H., Gabbay, Michael, Buntzen, Rodney R., Rees, C. David |
| Předmět: |
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| Zdroj: |
AIP Conference Proceedings; 2003, Vol. 676 Issue 1, p333, 6p |
| Abstrakt: |
We apply a newly developed time series analysis technique, the Hilbert-Huang Transform (HHT), to naturally occurring ocean electromagnetic data obtained from bottom-mounted sensors. The HHT was originally developed as an alternative to the Fourier power spectral density for the analysis of nonlinear phenomena in water waves. The HHT is applied to the data in two steps. In the first step, an empirical mode decomposition is used to extract individual oscillatory modes possessing different characteristic time scales. Unlike Fourier modes, however, these modes can vary in amplitude and frequency. In the second step, the Hilbert transform is used to determine physically meaningful instantaneous frequencies from these modes. We present results showing that the HHT provides a more compact representation of the ocean electromagnetic environment than the Fourier spectrum. In particular, the HHT is able to capture nonlinear wave phenomena associated with ocean swell in a single mode without the need for higher order harmonics. © 2003 American Institute of Physics [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
| Externí odkaz: |
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