Implementation

There are several ways to implement equation 4. The flow in Figure  presents the basic steps to implement and obtain the angle-domain common-image gathers for converted-wave data. The first step takes the final image $I({\bf m_{\xi}},h_\xi)$ and obtains two main components: first, the intermediate angle gathers, $\tan{\theta_0}$, using for example, the Fourier-domain approach Sava and Fomel (2003); second, the estimated step-out of the image, $\d$, using plane-wave destructors Fomel (2002). This step combines the two previous components, together with the $\gamma({\bf m_{\xi}})$-field, and uses equation 4 to form converted-wave angle-domain common-image gathers. The third step divides the PS-ADCIGs into P-ADCIGs and S-ADCIGs. The final step in the diagram flow is responsible for this operation.

 

flow Figure 2 Diagram flow for the subsurface-offset transformation to the angle domain. The flow diagram also presents the computation of the individual P-ADCIGs and S-ADCIGs.

The following sections present simple synthetic examples as well as a real-data result from the Gulf of Mexico.