Influence of the height of an elevated strike object on the enhancement of lightning radiated fields

We discuss in this paper the influence of the height of an elevated strike object on the magnitude of lightning radiated electric and magnetic fields. For the analysis, the transmission line (TL) return stroke model for the lightning channel is adopted and the strike object is represented by a uniform lossless transmission line. Analytical expressions derived recently by the authors for the radiated electric and magnetic fields are used to investigate the influence of the height of the elevated strike object Two specific cases of electrically-long and electrically-short strike objects are considered in the analysis. It is shown that, for both cases, the presence of a strike object results in an enhancement of the radiated electromagnetic field, compared to that of return strokes initiated at ground level. However, the enhancement is considerably larger for tall structures compared to short ones. The paper investigates additionally the effect of other parameters such as return stroke speed and reflection coefficients at the top and at the bottom of the strike object on the field enhancement.