The examples shown in this article demonstrate that the shot continuation scheme shifts shots successfully to different locations along the shot profile. Reflection events in an extrapolated shot gather agree kinematically with events recorded at the location.

The comparison of two shots after extrapolating them to the same location, offers new approaches to exploit seismic information. For example, discrepancies in the source wavelets of the two shots could be analyzed and resolved by a two-dimensional deconvolution. Kinematic differences in the two equivalent shot gathers are probably related to perturbations from the assumed constant velocity model. In the introduction, I explained how the correlation of extrapolated shot gathers can be used for velocity analysis. Since the geometry of the shifted shot gather can be freely chosen by the processor, the operation might additionally provide a tool for regularizing or binning seismic field data.

But before many of these applications can be successfully implemented, the amplitude of the shot continuation impulse response has to be improved, following the approaches utilized in the derivation of a sophisticated offset continuation operator.

Generalizing the shot continuation operator to variable velocity media will probably prove to be as difficult a task as generalizing the dip moveout operator. But as in DMO, a constant velocity approximation should be acceptable for a wide range of applications.

11/17/1997