A spatially-filtered FDTD sub-gridding scheme for ground penetrating radar scenarios

This paper demonstrates an FDTD sub-gridding scheme, employing spatial-filtering to ensure that coarse and dense mesh regions can be run at the time step of the coarse grid in a stable fashion, applied to ground-penetrating radar scenarios involving object detection in lossy, dispersive media. To that end, a spatially-filtered FDTD technique, which overcomes the Courant stability limit without resorting to implicit time integration, is extended to dispersive media modeled with an auxiliary differential equation (ADE)-FDTD method. Numerical examples are provided to show the accuracy and efficiency of the proposed approach.