Complex image model for ground-penetrating radar antennas

A method of combining the complex image method with the constant Q assumption is derived, which enables the calculation of complex image parameters once for the whole frequency range in the general half-space case. The mixed potential method of moments is then used to model horizontal wire dipoles near a lossy half-space, using pulse-basis functions and point matching. The method is demonstrated by the modeling of two types of wire dipole. A conductive half-wave dipole shows excellent agreement with NEC-S. The current distribution of a 3.4 m resistively loaded dipole across the frequency range 0-512 MHz is also calculated and transformed to the time domain. The result agrees with published measurements. The time required on a workstation was reduced to 4/s per frequency point.