DMO/AMO in the presence of caustics

Dip moveout (DMO) and azimuth moveout (AMO) are considered in a general framework that allows for lateral variations in the velocity model, including those which generate caustics in the wavefield. DMO and AMO are constructed through the composition of operators, using the scattering angle and azimuth parameterization. In this parameterization, impulse responses are computed in a gaussian gas lens model. Because of the different parameterization, these impulse responses are somewhat different than those shown traditionally. The results clearly show how errors can be introduced by assuming, for example, a constant velocity-gradient model when the true model is laterally heterogeneous.