Translations:Implementation of migration/25/en

The traveltime for a primary reflection is the total two-way (i.e., down and up) time for a path originating at source point S, reflected at depth point D, and received at receiver point R. Associated with each trace are two identification numbers, one for the source S and the other for the receiver R. We pull out the respective tables for these two identification numbers. We add the two tables together element by element. The result is a ${\rm {3D}}$ table for the two-way traveltimes for that seismic trace.