Weighted stacking of 3-D converted-wave data for birefringent media

Richard Andrew Bale

This paper describes a proposed method for weighted stacking of 3-D converted-wave data to give geometry-independent estimates of the S1 and S2 wavefields in the presence of shear-wave splitting. The method can also account for offset dependent amplitudes, which generally cannot be neglected for converted-wave data. The stacking procedure uses an estimate of the principal axis direction, but does not require information on the propagation differences between S1 and S2 modes. The stack normalization scalars are dependent on both acquisition geometry and principal axis direction. These are computed for a simple cross-spread example, to derive S1 and S2 "effective fold" maps. The maps show features that are related to the interplay between geometry and principal axis direction.