Reverse time migration in vertical and tilted orthorhombic media

Abstract

In this paper we derive a stable second order wave equation for reverse time migration in arbitrarily heterogeneous 3D orthorhombic media (ORT) with vertical and tilted symmetry axis. The formulation is equivalent to the first order elastic wave equation, thus it is physically stable and is a natural extension of the wave equations in VTI and TTI media. We compute the reverse time migration impulse responses for tilted orthorhombic media and demonstrate that our method provides stable and high quality RTM images in more general anisotropy media.