Dispersive FDTD Scheme and Surface Impedance Boundary Condition for Modeling Pulse Propagation in Very Lossy Medium

A dispersive surface impedance boundary condition (SIBC) is implemented in a dispersive finite-difference time-domain (FDTD) scheme to model pulse propagation and scattering from an aquifer, which has high permittivity and high conductivity. A quadratic complex rational function (QCRF) is adopted to model the dispersive media over a wide frequency band for implementing the dispersive FDTD scheme. The proposed method is demonstrated by simulating the operation of ground-penetrating radar (GPR) in detecting water table. Group delay and pulse-broadening parameter (PBP) are defined to analyze the deformation of pulses propagating in a dispersive lossy medium.