This work shows practical applications to the gaussian beam filter suggested by Pestana (1991). This filter can expand the seismic data, recorded in z = 0, into gaussian beams, for all offsets and all angular directions. It is formed by two parameters which are independents of the seismic model. These two parameters result from making both the source-point coordinate and the travel time complex in the classical representation of the point-source response. Gaussian beams are frequency-domain entities which combine the directional properties of plane waves with a finite support. After a complete demonstration of the filter, we show the first practical application: migration of zero offset data. The model that will be migrated, must be discretized into a regular grid, where the downward extrapolation is performed by an operator based in the free-space Green's function. The contribution for each beam is summed in each frequency and the final migration is obtained after imaging. The results present little edge effect and reductions in migration noises. We also present another practical application, which is the separation of elastic wavefield. The velocities in the layer near the surface must be known. Again, we use the filter to expand two dimensional data into gaussian beams. Performing a tau - p transform and using a rotation matrix, we can get the wave field separated into the components P and SV.
Gaussian Beam; Migration; Separation of P-SV waves
