Influence of interface roughness and heterogeneities on the waveguide inversion of dispersive GPR data

To investigate the influence of interface roughness and heterogeneous media on the inversion of dispersive GPR data, we performed 3D FDTD modeling with GPRMAX. For both the broadside and endfire source-receiver configurations the responses were calculated for models with different interface roughness and for models that include media with heterogeneities in their dielectric properties. Due to the use of multiple source-receiver offsets to calculate the phase-velocity spectrum, the signal to noise ratio was relatively good and for low interface roughness the medium properties could be reasonably well reconstructed. Only for the largest interface roughness the data contained significant diffractions and the medium properties could not be reliably reconstructed. For variations of the relative permittivity values equal to 10% and 20%, the model parameters could still be relatively well reconstructed.