ABSTRACT
Fourier transform decomposes a nonlinear waveform into a fundamental frequency component and its harmonics. As a result, the energy of a nonlinear wave is spread into higher frequencies. This may produce difficulties in the interpretation of wave propagation and quantification of wave dynamic properties such as the energy flux of the wave field. Recently, Norden Huang and his colleagues developed a new analysis technique, the Hilbert-Huang transformation (HHT). Through analytical examples, they demonstrated the excellent frequency and temporal resolution of HHT for analyzing nonstationary and nonlinear signals [1, 2].
