A Channel-Base Current Function for Lightning Return-Stroke Modeling

A mathematical function for the approximation of various lightning channel-base current waveshapes, which can be included in different lightning return-stroke models is presented in this paper. Its derivative, integral, and Fourier transform are determined analytically. The parameters of this function are also calculated according to the waveshapes of the first positive, the first and subsequent negative stroke channel-base currents as given in the International Standard IEC 62305-1.