Generalized migration

Anisotropic ADCIGs are based on the generalization of integral migration to the computation of a prestack image that includes the subsurface-offset dimension ($h_{\xi}$) in addition to the usual image depth ($z_{\xi}$) and midpoint ($m_{\xi}$). Figure  illustrates the subsurface-offset dimension: the image point $\left(m_{\xi},h_{\xi},z_{\xi}\right)$ belongs to the migration response of an impulse recorded at midpoint m_D, surface offset h_D and travel time t_D, provided that the travel time along the source and receiver paths (of length L_s and L_r, respectively) is equal to t_D.

 

imp-resp Figure 1 Illustration of generalized migration, where the prestack image is a function of the subsurface offset and $\gamma$ and $\alpha_x$ are the group aperture and dip angles, respectively.