Generalized Group- and Phase-domains Moveout Approximations for Converted-wave in a Horizontal and Homogeneous VTI Layer

For a horizontal and homogeneous transversely isotropic reflector with a vertical symmetry axis (VTI), we derive the generalized moveout approximations for P-SV converted-wave in group (t-x) domain and phase (τ-p) domain. They are called generalized approximation due to following the concept proposed by Fomel and Stovas. Both generalized moveout approximations include five parameters, separately; three parameters are determined from the zero-offset (horizontal slowness) ray and other two parameters are obtained from a non-zero offset (horizontal slowness) ray in group (phase) domain. The accuracy of our approximations is tested on a VTI model. Numerical results show that our group-domain approximation has good accuracy even for the large offset; our phase-domain approximation is equivalent to the exact solution. The potential applications of the proposed approximations include seismic modeling, traveltime inversion etc in a horizontal and homogeneous VTI layer.