An Examination of the Multi-Peaked Analytically Extended Function for   Approximation of Lightning Channel-Base Currents
  A multi-peaked version of the analytically extended function (AEF) intended for approximation of multi-peaked lightning current wave-forms will be presented along with some of its basic properties. A general framework for estimating the parameters of the AEF using the Marquardt least-squares method (MLSM) for a waveform with an arbitrary (finite) number of peaks as well as a given charge trans-fer and specific energy will also be described. This framework is used to find parameters for some common single-peak wave-forms and some advantages and disadvantages of the approach will be discussed. 
Karl Lundeng{\aa}rd, Milica Ran\v{c}i\'c, Vesna Javor and Sergei   Silvestrov
physics.comp-ph