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While the methodologies described in this paper are valid for general
linear operators, they have several fundamental limitations. Most
importantly, they require an accurate forward modeling operator: both
the physics of wave propagation and the true earth velocity must be
accurately modeled.
While the physics of wave-propagation is broadly understood, earth
velocity models are never completely true-to-life.
Another important caveat is that the ``wave-equation methods''
outlined here require the data and models to be represented on a
regular grid.
While we can choose our model-space, prestack seismic data is never
recorded on a perfectly regular grid. Before we can apply any
wave-equation technique (such as those described here), we need to
regularize the data.
Chemingui (1999) and Fomel (2000) provide two
different approaches to solving this problem.

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Stanford Exploration Project

4/29/2001