Processing Techniques to Extract Surface Wave Dispersion Curve from 3D Seismic Acquisition

The wide diffusion of 3D seismic surveying introduces the need of processing techniques able to extract dispersion curves from data acquired with 2D arrays. In this work we evaluate two processing techniques: the multidimensional Fourier transform and the Frequency Domain Beamforming method. Synthetics and real data have been analysed with the two methods for this purpose. Synthetic data has been obtained with a finite elements modelling and the computed dispersion curves have been compared with the theoretical one. In the analysis of real data the obtained dispersion curves have been compared with the one achieved through a linear array acquisition. The two tested processing methods have been able to correctly identify the fundamental and higher modes of propagation. The curves obtained with the two techniques do not differentiates significantly one from the other and are in agreement with the one obtained by a linear array and theoretical one. So, no advantages in choosing a specific method emerges in terms of result quality. However Beamforming method is more expensive for what concerns the computation.