VHF Direction Finder for Lightning Location

A VHF direction finder based on the technique originally proposed by Oetzel and Pierce for the detection of sferics from lightning has been field tested. Cianos et al. reported a successful test of the same technique using sferics at 30 MHz. In our measurements, sferics in the frequency range 82–88 MHz are received by two antennas separated by a distance of 115 m and the angles of arrival are calculated from the differences in the time of arrival of sferics at the two antennas. These measurements are compared with radar observations and show good agreement. Even when the observing station is surrounded by thunderstorms in many directions, the direction finder gave accurate angles of arrival. The direction finder located storms up to a range of 100 km and the range can be extended to about 160 km by suitable choice of the field site.