Using sparse S transform and sparse-slant stacking for the estimation of the group velocity of surface waves

Dolatabadi, Reza (University of Tehran) | Gholami, Ali (University of Tehran) | Askari, Roohollah (Michigan Technological University)


Summery In the multichannel analysis of surface wave (MASW) method, the conventional procedure obtains an S-wave velocity model based on the inversion of the phase velocity. However, the group velocity inversion has some advantages over the phase velocity; in particular, the group velocity does not require an estimation of the initial phase, nor to have a dense array of geophones. However, the estimation of the group velocity is not very straightforward due to the uncertainties associated with the transformation by which the group velocity is calculated. In this study, we introduce a new approach for the estimation the group velocity of the surface waves using the sparse S transform and sparse slant stacking. Compare to the conventional methods for the estimation of the group velocity using the generalized S transform, our approach does not require any adjustment to the Gaussian window in the transformation while yields a more accurate estimation of the group velocity.