Subsurface-scattering calculations via the 3D FDTD method employing PML ABC for layered media

The finite-difference time-domain (FDTD) method is suitable for solving scattering problems that contain several inhomogeneities such as multiple objects of different material properties buried in a layered medium. The advantage of the FDTD method is that the number of unknowns remains the same and a small amount of extra modeling effort is needed for these problems. We have developed a three-dimensional (3D) FDTD computer program that employs pure scattered-field formulation and perfectly matched layers (PML) as the absorbing boundary condition (ABC) of choice. The purpose of this study is to model a subsurface radar and to observe and distinguish between the fields scattered from various buried objects with different parameters such as the size, depth, number, etc.