Characterizing a GPR antenna system by near-field electric field measurements

A method to determine current distributions on resistively loaded Wu-King-type antennas from sparse near-field measurements of the electric field is introduced. We use a parametric formulation of current flow and invert the measured data to determine the characteristic antenna parameters and input voltage wavelets that best explain the measured electric-field data. We compare modeled and measured electric-field data to show that our inversion method yields reasonable results and that our antenna model provides a means to correct for the effects of an antenna's finite length in migration/imaging algorithms. By modifying the description of the current distribution, our method may be adapted for various antenna types.