The ray-tracing algorithm for 3-D map de-migration/migration produces good results provided that the maximum dip of the layers under investigation is under the limit corresponding to the chosen velocity model.
The limitation occurs because of the geometrical definition of the method. This problem drives me to investigate Eikonal equation for time migration in order to go further in this project. At present time, it is hard to say whether this new study will provide an algorithm strong enough to perform de-migration and map migration of any kind of time model.