An ensemble-based variational inversion scheme

To develop the lightning physics and the new lightning protection theory and technology, inversion of thunderstorm charged model is should been done based on E-field data at the ground level, which is a practical way to study the thunderstorm charged structure. Traditional inversion methods always fail, for actual thunderstorm charged structure is extraordinarily complex and objective functions are strongly non-linear. To solve this problem, An Ensemble-Based Variational (EBVar) Inversion Scheme is presented. The inversion solution is obtained as a model state that maximizes the posterior probability distribution, via an unconstrained minimization of an arbitrary nonlinear cost function. This creates an important link between the control theory and Monte Carlo data inversion method. The use of linearized models, or adjoints, required for variational methods, is completely avoided.