Application of the Lienard‐Wiechert solution to a lightning return stroke model

The electric and magnetic fields associated with a lossless transmission line model of the return stroke are expressed as a convolution of the current waveform shape and the fields generated by a moving charge of amplitude one (i.e., the Lienard‐Wiechert solution for a unit charge). The representation can be used to compute the fields produced by a current waveform of non‐uniform velocity that propagates along a filament of arbitrary, but finite, curvature. To study numerically the effects of linear charge acceleration and channel curvature, two simple channel models are used: the linear and the hyperbolic.