(1) |

(2) |

In order to obtain a dip estimate for the events in the plane we
employ the method of Fomel (2002). This technique
estimates local stepouts with plane wave destructor filters. Only one
dip is estimated at every time and offset position, which makes this
method sensitive to crossing events or coherent
noise. A solution to this problem is to estimate multiple dips at every
location and to select those of interest Fomel (2002).
Once the dips have been estimated, the slowness can be computed in a
straightforward manner by mulitplying each dip estimate by
*t*/*x*. A map of local slowness (squared) is then obtained that need
only be converted to a velocity profile for a given CMP gather.

To achieve this goal, a NMO correction with an approximate velocity
trend can be applied to roughly flatten the hyperbolas. Finally, a median stack over
the *x* coordinate provides a reasonable estimate of *s ^{2}* as a
function of . To ensure local bad dip estimates do not skew
the results of the method, data points corresponding to atypical
slowness values are disregarded, and the final result is smoothed
in time. Once the estimate of slowness squared is obtained, we convert
it to

5/23/2004