Examination on Determination of Arrival Time of Electromagnetic Field Signals Radiated from Cloud-to-Ground Lightning by Theory of Natural Observation Method

摘要

Temporal fluctuation of electromagnetic fields signals observed in the natural environment is very complicated. As the method of the waveform analysis of such nonstationary signals, the theory of natural observation method is proposed. In this paper, the theory of natural observation method was applied to the electric field signals reflected between ionosphere and earth, radiated from cloud-to-ground lightning, observed in Honjo observation point. And the determination procedure of difference of arrival time using this theory is examined. As a result, it was clarified that the distance between observation point and strike point was obtained at the high accuracy by applying the theory of the natural observation method to this procedure.