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In the 3D case, as in the isotropic migration, the dispersion relation is split into *x* and *y* components as follows:
| |
(13) |

This two-way splitting causes numerical anisotropy, which can be remedied by a phase-correction filter Li (1991) in
the Fourier domain as follows:
| |
(14) |

where
| |
(15) |

where *v*_{p}^{r} is the reference vertical velocity, and are the reference anisotropy parameters, and and are the optimized finite-difference coefficients corresponding to the anisotropy parameters and .

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Stanford Exploration Project

4/5/2006