Analysis of lightning electromagnetic fields in the vicinity of a lossy ground, using a new antenna theory model

A new antenna theory approach is utilized to compute current distributions along the channel and electromagnetic fields due to a lightning return stroke. This model uses the method of moments (MoM) in the frequency domain for solving the governing electric field integral equation (EFIE). For the excitation of the wire antenna a new current source model is presented. In order to include effects of lossy ground, a simple modified image theory is applied. The method is adapted to the transient nature of lightning using an appropriate FFT algorithm.