The derivation of the AMO operator starts from the Fourier-domain formulation of DMO Hale (1984) and ``inverse'' DMO Liner (1990); Ronen (1987). However, because 3D prestack data is often irregularly sampled, AMO is applied as an integral operator in the time-space domain. The transformation is thoroughly defined in the midpoint-offset domain by the kinematics, the amplitude weights and the spatial extent (aperture) of the AMO impulse response.