Shot-Profile Dip Moveout
, by Biondo Biondi and Shuki Ronen
All the known Dip Moveout (DMO) methods require the seismic data to be sorted in midpoint and half offset coordinates. In this paper a DMO method for shot profiles is proposed.
The DMO operator in shot profiles is defined in a way analogous to the well known operator in constant-offset sections. The two operators are found to be equivalent and to have impulse responses with the same projection on the zero offset plane, i.e. the stacking plane. Therefore the application fo DMO in constant-offset sections or in shot profiles gives the same stacked section. DMO transforms the shot profiles to zero offset data to which may be applied any post stack migration.
Unfortunately the shot-profile DMO operator is space and time variant; thus its direct application would be computationally expensive. Instead, after a logarithmic transformation of both the coordinates the operator becomes time and space invariant, and then the procedure may be performed efficiently as a convolution in Fourier domain.
The performance of the algorithm is shown in field data examples and the results are compared with the conventional DMO in constant offset sections.
The sensitivity to inaccurate NMO velocity and the possibility of performing residual velocity analysis is also analyzed with the help of some synthetics examples.
STANFORD