dispersion curves for media with lateral-variation at different angles

The specification of soil surface layers is one of the most important parameters in civil engineering, geotechnics, and geophysics. the surface layer of the soil with lateral variation was modeled at different angles in finite element software. in each model, the shot was applied on two sides of the geophone array and the seismic wave data were recorded by geophones. using the windowing methods of dierent lengths and moving along the array, the various geophone data were placed in different windows. next, for each windowing, the frequency-wavenumber spectrum was obtained using the double fourier transform, and then, the dispersion curve was plotted. in this regard, the variations in the resolution of the frequency-wavenumber spectrum and dispersion curve were investigated for different window lengths. the phase velocity changes due to the changes in the lateral variation angles were also investigated. for the media with lateral variation, the dispersion curves could be obtained along the array and the location of the start and end of lateral variation in the corresponding phase velocity range could be achieved with acceptable accuracy, and the estimated phase velocity could be used as initial velocities in the inversion and specication of soil surface layers.