A wavelet packet based method for detecting lightning leaders in dE/dt signatures

The electric field derivative (dE/dt) radiation from lightning leaders are usually very weak, and it is hard to be recognized if the lightning strike is far from observation site. In this paper, Fourier analysis of a segment of noise contaminated dE/dt signal is conducted. Based on the identification of the noisy source and leader spectrum, a wavelet packed based method for detecting dE/dt signatures of lightning leaders is proposed and performed. The application of this method on the observation data show that obvious leader characteristic in dE/dt waveforms could be retrieved in weak leader radiations, and the recognized leader pulse coincide with synchronized measured high sensitivity E changes.