Regularization of ill-posed return stroke current identification problem

Using direct measurements of lightning magnetic and electric field by inverse problem formulation it is performed the identification of the lightning return stroke current. The approach starts from Fredholm integral equations of the first kind as engineering models and uses modular regularization procedures based on a spatial and time dependent harmonic reconstruction of the lightning current. All the preliminary evaluations appear to be in good agreement with the actual characterization models for return stroke current of the lightning; moreover the precision as regarded to the effect is considerably improved.