VHF Direction Finder Studies of Lightning

Abstract

The directions in which VHF pulses are received from thunderstorms are measured at the rate of over 600 s?1 with elapsed time also stored every 10 ms during bursts. This provides detailed information regarding the sequence of directions to an accuracy of ±5° for direction and ±3 ms for time of occurrence. VHF pulses from small bursts from the same direction show an initial spreading in time and a bunching effect toward the end. Three-dimensional (azimuth, elevation and time) pictures of VHF emissions from small bursts were obtained. An example is given showing wide ranging multiple flashes, together with evidence that the directions of concentrated emission may remain constant for several minutes.