Accuracy of finite-difference modeling of the acoustic wave equation

Recent interest in finite-difference modeling of the wave equation has raised questions regarding the degree of match between finite-difference solu-tions and solutions obtained by the more classical analytical approaches. This problem is studied by means of a comparison of seismograms computed for receivers located in the vicinity of a WI-degree wedge embedded in an infinite two-dimensional acoustic medium. The calculations were carried out both by the finite-difference method and by a more conventional eigenfunction expansion tech-nique. The results indicate the solutions arc in good agreement provided that the grid interval for the finite-difference method is sufficiently small. If the grid is too coarse, the signals com-puted by the finite-difference method become strongly dispersed, and agreement between th