The group velocity dispersion is easily calculated from the theoretical methods such as Resonance Scattering Theory (RST) and Sommerfeld-Waston transformation, however,it's difficult to extract the dispersion from experiment. In this paper,a simulation model based on the wavenumber integration and virtual source method is adopted to simulate the experiment,the source which is a pulse is emitted and the time series of the echo signal are got from the simulation model. The Wigner-ville jointly time-frequency distribution is applied to the time series of echo signal. The group velocity can be estimated from the group delays of the successive wavepackets, because the group delay can be estimated by the first-order moment of the Wigner-ville distribution along the time series. The group velocity dispersion extracted from the simulated echo signal is compared with dispersion from the resonance scattering theory, and they coincide very well.
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