This paper presents a 3D shot-profile migration approach in
ellipsoidal coordinates. The common form of ellipsoidal coordinates
generates confocal ellipsoidal shells well-positioned for propagating
turning waves in all azimuths. The numerical aspects of implementing
the corresponding dispersion relationship, though, are somewhat
problematic. We use an integral transform to recast the problem in a
way that facilitates numerical implementation. We note that the
similarity between the new ellipsoidal and elliptically anisotropic
media dispersion relationships allows us to use existing implicit
finite-difference extrapolation implementations. The impulse
responses demonstrate that the numerical solution is both accurate and
stable. Future work will focus on generating 3D shot-profile
migration results in the ellipsoidal coordinate system.
2009-04-13