AMO: Azimuth Moveout (AMO) is a partial-migration operator that can be effectively applied to interpolate and regularize seismic data. AMO can be used to improve the accuracy and reduce the computational cost of 3-D prestack imaging. For example, a 3-D prestack dataset can be drastically reduced in size by coherent partial-stacking after AMO. The reduced dataset can be then imaged by prestack depth migration, a process that would have been more expe nsive to apply to the original dataset. AMO can also be effectively used for regularizing data geometries (e.g., to correct for cable feather) and for interpolating unevenly and irregularly sampled land data. The AMO operator rotates the azimuth and modifies the offset of 3-D prestack data. It is analytically derived by cascading the forward and inverse 3-D DMO. The AMO algorithm is faster than prestack migration because the aperture of the AMO operator is smaller and decreases with time, compared to the aperture of the prestack migration operator which increases with time. The concept of AMO is fairly recent, having been developed at Stanford University by Biondo Biondi, one of the principals of 3DGeo, in 1994.

AMO is stricly derived from the wave equation and therefore carries the correct kinematic, phase and amplitude transformation. The dipping events are moved correctly when transforming or interpolating the data, in a manner that is consistent with the wave equation. This property sets AMO apart as a seismic interpolator from more conventional ones. Biondi and Chemingui (1994) show clearly how AMO preserves the dipping events after stack, in comparison with the industry standard sequence of NMO, DMO and stack. Dipping events are especially important for migration, because they determine the increase in image resolution after 3-D prestack or postack migration.

Biondi, B., Fomel, S., and Chemingui, N., 1998, Azimuth moveout for 3-D prestack imaging: Geophysics, 63, 574--578.

Biondi, B., and Chemingui, N., 1994, Transformation of 3-D prestack data by azimuth moveout: 64th Ann. Internat. Mtg., Soc. Expl. Geophys., Expanded Abstracts, 1541-1544.