Amplitude Preserving v(z) Pre-stack Kirchhoff Migration, Demigration and Modeling

B-11 AMPLITUDE PRESERVING V(Z) PRE-STACK KIRCHHOFF MIGRATION DEMIGRATION AND MODELING 1 Summary We analyze the true amplitude weights in time migration and demigration based on Bleistein’s Kirchhoff inversion and modeling formulas. In addition a geometrical spreading factor is derived for any dipping reflector in a v (z) medium. Finally we propose proper anti-aliasing formulas honoring sampling theory to preserve fidelity for 3-D migration and demigration. Introduction Kirchhoff prestack time migration is widely used in 3-D seismic data processing while Kirchhoff demigration is a useful tool to obtain a zero-offset data volume after Kirchhoff prestack time migration and stack. Arbitrary weights