Abstract
Several aspects of processing P-SV data are more complex than the
conventional P-wave processing case. In this study, four processes
that pertain directly to the seismic imaging problem are examined:
S1-S2 wave field separation, P-SV common conversion point (CCP) mapping,
moveout correction and time migration. If a low-velocity near surface
layer is present, fast and slow (split) shear waves recorded at the
free surface can be separated prior to stack using a simple co-ordinate
rotation. Current methods of CCP gathering for multifold P-SV data
may result in excessive loss of spatial resolution. A new method
is proposed to solve this problem by mapping each data sample to
its correct conversion pointposition before stacking. Examples of
this technique are provided using synthetic data. The coefficients
of the power series expansion for the squared travehime for P-SV
reflections are similar to the coefficients for the equivalent power
series in the P-P case, and suggest that P-SV moveout is nearly hyperbolic.
However, the hyperbolic moveout approximation is less accurate for
P-SV events than P-P events. Finally, conventional time migration
appears to produce valid results when applied to P-SV data after
stack.
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