Stabilizing explicit ω - x migration using local WKBJ operators

Chad M. Hogan, Gary F. Margrave

A new operator for the GPSPI migration algorithm is introduced. It is shown that a suitably chosen vertical velocity profile v(z) with a linear positive gradient limits a point source at depth so that the entire upper hemisphere of its wavefront reaches the surface within a finite aperture. This concept is used to design a WKBJ operator. The resulting operator is shown to have a finite aperture and is stable when localized.