Relation between Dips of Prestack Time Migrated & Unmigrated Data

Abstract

Relation between dips of post-stack migrated and unmigrated data is well known and easy to derive. A similar relation between dips of pre-stack migrated and unmigrated constant offset data is not available in literature and is calculated here. Since migration outputs for multiple offsets are available, the formula valid for all offsets gives us a tool to check the correctness of the migration velocity model. The formula is also used to study how a reflector with constant dip gets curved in constant offset gathers. Further, a handy formula for prestack migration aperture is derived and its variations with offset, depth and dip angle studied.