3-D Impulse responses

In this section, we compare the 3-D impulse responses of the anisotropic Common Azimuth migration operator with the corresponding isotropic one. For this paper, we consider impulse responses for elliptical anisotropy only. The vertical P wave velocity in the medium is 2000 m/s. The anisotropic parameters $\epsilon$ and $\delta$ are both equal to 0.15. Figures and show in-line sections of the 3-D impulse responses for elliptically anisotropic and isotropic media respectively. These figures clearly show the difference of incorporating anisotropy into the Common Azimuth downward continuation operator, especially for energy propagating at moderate to steep angles. Figures and show cross-line sections of the 3-D impulse responses for elliptically anisotropic and isotropic media respectively. Again it can be seen that there are significant differences for energy propagating at moderate to steep angles once anisotropy is incorporated into the Common Azimuth operator. Finally, Figures and show depth slices of the 3-D impulse responses for elliptically anisotropic and isotropic media respectively. Again, we also observe significant differences between the two depth slices, especially the more elliptical nature of the depth slice for the anisotropic operator.

 

aniso15_inline
Figure 4 An inline slice of the 3D impulse response in an elliptically anisotropic media at y=0 m.

 

iso_inline
Figure 5 An inline slice of the 3D impulse response in an isotropic media at y=0 m

 

aniso15_xline
Figure 6 A cross-line slice of the 3D impulse response in an elliptically anisotropic media at x=0 m

 

iso_xline
Figure 7 A cross-line slice of the 3D impulse response in an isotropic media at x=0 m

 

aniso15_depth_slice
Figure 8 A horizontal slice of the 3D impulse response in an elliptically anisotropic media at a depth of z=600 m.

 

iso_depth_slice
Figure 9 A horizontal slice of the 3D impulse response in an isotropic medium at z=600 m.