Improvement of the FDTD method for the study of wave penetration inside a valley

The finite difference time domain (FDTD) algorithm generally needs a three-dimensional (3-D), rectilinear computational volume. For some applications, one part of this volume is not useful, then taking a rectilinear total volume can require unnecessary memory and computation time. This paper introduces a method to reduce the computer resources for certain applications. The example of wave penetration inside a valley illustrates our approach.