Arbitrarily wide-angle wave equation absorbing boundary condition in acoustic numerical simulation

To attenuate artificial edge reflections arising at truncation boundary, stable and effective absorbing boundary conditions (ABC) should be applied in seismic numerical simulation. In this paper, we use a high accurate one-way wave equation, named arbitrarily wide-angle wave equation (AWWE), as ABC in second-order acoustic wave equation simulation. We give out the corresponding discrete formulation of the boundary condition using the finite-difference method. Meanwhile, the corner regions are carefully treated. The numerical simulations of a homogeneous medium and 2D Marmousi model show that AWWE boundary condition can adapt to a wide range of incident angle and has a better absorption effect than second-order paraxial approximations (CE2 in short). The computation efficiency of the AWWE boundary condition is almostidentical to CE2.In addition, such an ABC has no influence to the interior stability.