We have presented an approach to time migration based on angle gathers. The output of this procedure are migrated angle gathers - images for constant reflection angles. When stacked together, angle gathers can produce the same output as the conventional common-offset gathers. Looking at angle gathers individually opens new possibilities for amplitude-versus-angle studies and for velocity analysis.

Our first synthetic tests produced promising results. In the future, we plan to study the amplitude behavior of angle-gather migration and the velocity sensitivity more carefully. We also plan to investigate the frequency-domain approaches to this method. Initial results indicate that angle-gather migration is comparable to offset-domain migration for angles less than the angle at which rays exit the sides of the model, but further study will hopefully allow us to extract useful information from the larger angles as well. Although the major advantages of angle gathers lay in the depth migration domain, it is easier to analyze the time migration results because of their theoretical simplicity.

4/20/1999