Modelling of the whole electric field changes during a close lightning discharge

In this paper we propose a simple model to calculate the electric field waveforms, radiated both by the leader and by the return stroke phases of the lightning discharge. In this model, we consider a simple representation of the discharge, whereby its trajectory is represented by a vertical channel and the ground is considered as a perfectly conducting plane. To determine the electric field change associated with the downwards leader, its charge per unit length was expressed as a function of the current and the speed of the return stroke. The obtained results are found to be in accordance with experimental records obtained during the artificially triggered lightning campaigns carried out between 1993 and 1995 in Florida.