MIGRATION OF P-WAVE REFLECTION DATA IN TRANSVERSELY ISOTROPIC MEDIA

Wave propagation in transversely isotropic media is governed by the ho rizontal and vertical wave velocities. The quasi-P(qP) wavefront is no t an ellipse; therefore, the propagation cannot be described by the wa ve equation appropriate for elliptically anisotropic media. However, f or a limited range of angles from the vertical, the dispersion relatio n for qP-waves can be approximated by an ellipse. The horizontal veloc ity necessary for this approximation is different from the true horizo ntal velocity and depends upon the physical properties of the media. I n the method described here, seismic data is migrated using a 45-degre e wave equation for elliptically anisotropic media with the horizontal velocity determined by comparing the 45-degree elliptical dispersion relation and the quasi-P-dispersion relation. The method is demonstrat ed for some synthetic data sets.