Reflection tomography versus stacking velocity analysis

The travel-time inversion of reflected arrivals reconstructs the structure of the main interfaces with a precision comparable to the seismic wavelength. The resolution of the conventional stacking velocity analysis is lower, i.e. of the order of the seismic spread length. Furthermore, the stacking velocity field is defined in the time domain, and its conversion to the depth domain is not straightforward. Both methods require selecting: this is quite difficult and time consuming for the pre-stack reflected events, but simpler and inexpensive for the velocity spectra. There is thus a tradeoff between the two approaches in terms of costs and benefits. In this paper we compare the main features of the two methods by applying them to different synthetic models of increasing complexity. We modelled the related seismograms using the Fourier pseudo-spectral method.