f Finite-difference prestack reverse time migration using P-SV wave equation

Prestack Reverse Time Migration (RTM) is performed using a first-order system of hyperbolic elastic equations of motion and constitutive laws expressed in terms of particle velocities and stresses. It is well known that the RTM procedure must contain three important steps, i.e., it must apply (a) the imaging condition, (b) the reverse time extrapolation and (c) the extraction of amplitudes from the seismic data in order to build the final images. Here the above mentioned steps are implemented using the same code, which is a two-dimensional explicit finite-difference scheme. It is of second-order accuracy in time and fourth-order accuracy in space.