DISCUSSION

The ray tracing example in this paper shows that ray tracing is stopped when the tangent of the ray is close to horizontal, because all the reflector dips in the reflectivity model are less than 90-degree. This is unnecessary. Ray tracing can be continued as the ray path turns. Computation of Gaussian beams for the turning ray path is equally possible. When this is accomplished, Gaussian beam migration can migrate dips up to 360-degrees. This ability can be of great utility in the migration of earthquake seismic data.