Migration = focus + map
, by Joe Dellinger & Francis Muir
Depth migration is viewed as a two-step process: the data is focused and then the focused
image is mapped to true depth. It is not necessary to know the complete velocity and
anisotropy structure to focus the data, but to make a true depth image it is. As a simple
example, we consider the case of depth migration in the presence of elliptical anisotropy
with an arbitrary axis. In this case standard isotropic constant-velocity migration focuses
the data exactly, but a linear transformation is still required to map the result to a true
depth image.
STANFORD