f Target oriented migration by means of controlled illumination

Stacking of common receiver gathers at the surface produces plane wave responses of the subsurface, Taner (1976). Since these plane wave responses are physical experiments, wave equation based extrapolation techniques (pre-stack) can be used to migrate or redatum these responses. However, due to the inhomogeneitics of the subsurface; the wave front will be (seriously) distorted when arriving at the level of interest, the target zone, (Fig 1).