Ground radar simulation for archaeological applications

This work presents a new modelling scheme for the simulation of electromagnetic radio waves, based on a full-field simulator. Maxwell's equations are modified in order to include dielectric attenuation processes, such as bound- and free-water relaxation, ice relaxation and the Maxwell-Wagner effect. The new equations are obtained by assuming a permittivity relaxation function represented by a generalized Zener model. The convolution integral introduced by the relaxation formulation is circumvented by defining new hidden field variables, each corresponding to a different dielectric relaxation. The equations are solved numerically by using the Fourier pseudospectral operator for computing the spatial derivatives and a new time-splitting integration algorithm that circumvents the stiffness of the differential equations. The program is used to evaluate the georadar electromagnetic response of a Japanese burial site, in particular, a stone coffin-like structure.