Iterative method for waveshape restoration of directly measured lightning flash currents

A simple and efficient iterative method for the removal of superimposed reflections caused by a stroke tower from digitally recorded lightning flash currents is presented. The method has been demonstrated on several typical cases and the reliability of input data is discussed. The method is extended to the estimation of lightning channel surge impedance, completing lightning current data independently of stroke tower parameters. Complete data of a lightning source model for the transient analysis of lightning strokes to electric power systems may be estimated in this way. The method also enables comparison of lightning data obtained by measurements on both short and very tall towers.