Lightning ground-flash multiple-stroke discriminator

A new technique for the determination of the incidence of lightning multiple-stroke ground flashes is described that is considerably simpler in application than many of those previously used. The technique involves the use of a proven lightning ground-flash counter, together with a new electronic circuit that classifies subsequent strokes in serial order. Preliminary results from a trial period of operation with the new instrument are presented and good agreement is apparent with the results of techniques employing rotating-camera photography and closed-circuit television video-recording systems.