PULSE DISTORTION IN-DEPTH MIGRATION

When migrating seismic primary reflections obtained from arbitrary sou rce-receiver configurations (e.g., common shot or constant offset) int o depth, a pulse distortion occurs along the reflector. This distortio n exists even if the migration was performed using the correct velocit y model. Regardless of the migration algorithm, this distortion is a c onsequence of varying reflection angle, reflector dip, and/or velocity variation. The relationship between the original time pulse and the d epth pulse after migration can be explained and quantified in terms of a prestack, Kirchhoff-type, diffraction-stack migration theory.