Applications and Comparisons of the Frequency Domain and the 45-degree Omega-Finite Difference Migration Algorithms
, by Heloise Bloxsom and Rick Ottolini

To study and compare the output quality of frequency domain and 45-degree
finite difference migration algorithms, two different datasets of
exploration interest are examined: a "stratified earth" and a "laterally
varying earth." The migration algorithms and methods are briefly reviewed.
Comparisons of the stratified-earth migrations show that the constant
velocity f-k and the constant velocity 45-degree monocromatic algorithm
produce nearly identical results. For interpretation, the V = V(t)
frequency comain or the V = V(z) 45-degree finite difference algorithms
are more correct and produce sections of comparable quality. Migrations
of the laterally varying earth show that V = V(x,z) algorithms must be
used, and that the velocity model dramatically affects the output picture.
Two current fields of research are benefitted by V = V(x,z) migration
algorithms: the nature of the continental crust at depth, and the correct
imaging of sediments under thrust zones.