Fdtd, Electrodynamics, Ground Penetrating Radar, Editors Pick, Thoughts And Theory.
An approach used by many researchers is approximation of the complex permittivity using multi-pole Debye expansion with multiple relaxation times and a dimensionless weights in form [12] being εn and τ0,n (for n=1,2,…,N) the change in the permittivity (weights) and relaxation times of the Debye