2.5 D Finite-Difference Solution Of The Acoustic Wave Equation

Finite differences applied to the full 3-D wave equation is a rather time consuming process. However, in the 2.5-D situation, we can take advantage from the medium simmetry. By taking the Fourier transform in the out-of-plane direction, the 3-D problem can be reduced to a 2-D one. The third dimension is taken in to account by a sum over the corresponding wave vector component. In this way, the 2.5-D finite differences program can improved by a factor that increases with the size of the model. Numerical examples show the applicability of the method.