Observation of lightning discharge processes using broadband radio interferometer

A broadband radio interferometer, one of the sophisticated techniques to reveal the mechanism of lightning discharges, has been designed and tested by authors and it gave us useful results on locating sources of electromagnetic radiation from lightning discharges and reconstructing lightning discharge channels. The advantage of this technique is the capability of positioning radiation sources for both isolated pulses and pulse bursts. A single-station lightning location experiment using radio interferometer has been carried out in Darwin, Australia in December 1997. One of the experimental result shows a series of strokes occurred in a negative cloud to ground discharge. Radiation of cloud discharge activities was also recorded during the early stages of initial and subsequent leaders to ground. The subsequent leaders have the same channel path with the first leader. Period of this cloud to ground flash was in the range of hundred milliseconds. The location of radio frequency sources emitted from lightning is drawn both in two dimensions map and in time sequences.