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An alternative to the wavefield perturbation definition
in equation (13) is given by the Rytov approximation.
If we can estimate the accumulated phase differences
between the two wavefields at every depth level
| |
(15) |

we can compute another wavefield perturbation using
the relation:
| |
(16) |

which is directly derived from equation (9).
With this definition of the wavefield perturbation,
we can compute another slowness perturbation which
corresponds to the Rytov approximation
| |
(17) |

using the same backprojection operator.

** Next:** Differential image perturbation
** Up:** WEMVA theory
** Previous:** Born image perturbation
Stanford Exploration Project

10/14/2003