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Common-azimuth data represent subsets of 3D prestack data that
have been recorded or transformed to a common azimuth,
which corresponds to zero cross-line offsets ().
Stolt migration for common-azimuth data involves
the use of the following dispersion relation (9):
| |
(40) |

where the depth wavenumber for the common-azimuth dataset () is
written as
| |
(41) |

We can rewrite dispersion.true and disp.true
for a given reference velocity (*v*_{0}) and obtain the corresponding depth
wavenumbers and .Mathematically, the goal of common-azimuth Stolt residual migrations
is also to obtain from .
Again, we can achieve this by eliminating the
frequency from the expressions for and ,
which leads to the 3D common-azimuth residual migration equations:

| |
(42) |

where, by definition, .If we make the change of variables
| |
(43) |

we obtain a simplified version of myresmig-ca:
| |
(44) |

For 2D data, where *k*_{m}_{y}=0,
and ,myresmig-ca reduce to the 2D prestack
myresmig-2d-pr and post-stack
myresmig-2d-po forms.

** Next:** Examples
** Up:** Prestack residual migration
** Previous:** Prestack Stolt residual migration
Stanford Exploration Project

11/4/2004