Relation between Dips of Prestack Time Migrated & Unmigrated Data

TL;DR

This paper derives a new formula linking dips of pre-stack migrated and unmigrated data, providing a tool to validate migration velocity models and analyze reflector curvature in seismic imaging.

Contribution

It introduces a novel relation between dips of pre-stack migrated and unmigrated data, not previously available in literature, and explores its applications in migration validation and reflector analysis.

Findings

Derived a formula valid for all offsets to check migration velocity models.

Analyzed how reflectors with constant dip curve in constant offset gathers.

Developed a formula for prestack migration aperture and studied its variations.

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.