Localization of thunder source and reconstruction of lightning channel geometry using sound data

Thunder waves generated by lightning ground and cloud flashes are considered to be one of strong natural sound source. Even though the strongest thunder signatures are generated at the return stroke stage, thunder signals generated at other events also can be strong enough to record using a sensitive system. In this study, it was attempted to construct the channel geometry of cloud and ground flashes by locating the temporal and spatial variation of thunder sources. The system was consisted of 3 Bruel & Kjaer type 4198 prepolarized, free field 1/2´ microphones placed at difference locations. A mathematical model using the time of arrival method was developed to calculate the location of thunder sources. Five lightning flashes were reconstructed using the recorded thunder signatures. Possible effects that can cause by atmospheric conditions were neglected. However, numerical calculations suggest that the possible error on the location due to miscalculations of time is less than 2%. Accuracy of the calculations can be improved by increasing the number of microphones. Therefore, we suggests that the thunder signal generated by lightning ground and cloud flashes could be used to study the channel geometry of lightning.