Simulations of GPR in dispersive media using a frequency-dependent PSTD algorithm

Recently an efficient pseudospectral time-domain (PSTD) algorithm has been developed to solve partial differential equations in computational electrom agnetics and acoustics. It uses the fast Fourier transform (FFT) algorithm to approximate spatial derivatives, and the perfectly matched layer (PML) t o eliminate the wraparound effect, Due to its high accuracy in the spatial derivatives, this method requires a significantly smaller number of unknown s than a conventional finite-difference time-domain (FDTD) method when solv ing large-scale problems. In this work, we further extend the PSTD algorith m to frequency-dependent media and apply the algorithm to simulate ground-p enetrating radar (GPR) measurements in a dispersive earth. The dispersion o f the soil is treated by the recursive convolution approaches. The converge nce property of the PSTD algorithm is investigated for the scattering of a dispersive cylinder, Multidimensional large-scale problems in GPR measureme nts are presented to demonstrate the efficiency of this frequency-dependent PSTD algorithm.