Figure is the impulse response of isotropic phase-shift with an anisotropic correction operator. Figure is the impulse response of isotropic FFD with an anisotropic correction operator. The reference velocity for the FFD is 1500 m/s. We use 39 points for the explicit correction operator in Figures and . Since the medium is homogeneous, we can also extrapolate the wavefield with anisotropic phase-shift (equation (5)). Figure is the impulse response of anisotropic phase-shift. Comparing Figures , and , the impulse response of the isotropic operator with an anisotropic correction operator is the same as that of the anisotropic phase-shift method for propagating angles up to almost .It is different from anisotropic phase-shift for higher angles because the explicit correction operator is not same as the one for anisotropic phase-shift for wavenumbers close to the evanescent area.

10/23/2004