For *P*-wave datasets, angle-domain common-image gathers
[e.g., Prucha et al. (1999); de Bruin et al. (1991)]
decompose reflected seismic energy into components from
specific opening angles ().
Since the *PS*-wave polarity reversal occurs at normal incidence
(), the angle-domain common-image gathers provide a
natural domain in which to address the polarity reversal problem.
Moreover, analyzing angle gathers for converted wave seismic data
may lead to:
velocity analysis and amplitude versus angle
analysis for converted waves.

In this work we present a theoretical discussion of the
polarity reversal problem.
We image *PS*-wave data into offset-domain CIGs with a
prestack recursive depth migration algorithm.
We use the radial-trace transformation introduced by
Sava and Fomel (2000) to obtain
angle-domain gathers after migration.
We reinterpret the opening angle () for the case
of converted waves, this leads to a solution of the polarity
reversal problem that is valid for any structurally
complex media.

4/29/2001