Power spectral density function and spatial autocorrelation of the ambient vibration full-wavefield generated by a distribution of spatially correlated surface sources

Synthetic dispersion curves are here computed in the frame of an ambient-vibration fullwavefield model, which relies on the description of both ambient-vibration ground displacement and its sources as stochastic fields defined on the Earth's surface, stationary in time and homogeneous in space. In this model, previously developed for computing synthetic Horizontal-to-Vertical Spectral Ratio curves, the power spectral density function and the spatial autocorrelation of the displacement are naturally described as functions of the power spectral density function of the generating forces and of the subsoil properties (via the relevant Green's function), by also accounting for spatial correlation of these forces. Dispersion curves are computed from the displacement power spectral density function and from the spatial autocorrelation according with the well-known f-k and SPAC techniques, respectively. Two examples illustrate the way this new ambient-vibration model works, showing its possible use in better understanding the role of the surface waves in forming the dispersion curves, as well as its capability to capture some remarkable experimental findings.