Estimation of the p-wave velocity profile of elastic real data based on surface wave inversion

Recently, we proposed an analytical approach to invert for a smoothly varying near-surface P-wave velocity profile that has a squared slowness linearly decreasing with depth. The exact solution for such a velocity profile in the acoustic approximation can be expressed in terms of Airy functions and leads to a dispersion equation. The method was successfully applied to synthetic elastic data with small Vs/Vp-ratio. Here, we apply the method to land data. The result agrees with that of multi-layered inversion, confirming its potential to provide an initial P-wave velocity model for acoustic full waveform inversion. Compared to multi-layered inversion, the method is simpler to use and produces a smooth model characterized by three parameters. In some cases, having a smooth rather than a blocky initial model for full waveform inversion is more appropriate