Abstract: A lightning detection system utilizes a gated magnetic direction finder for determining the range and direction of lightning discharges to ground. Logic circuitry is provided for controlling gating circuits within the direction finder so that the direction measurement is made during the initial few microseconds of the return stroke waveform, thereby minimizing errors caused by nonvertical lightning channels to ground, branches and intracloud discharges. Distance measurements are made by analyzing the amplitude of the detected return stroke waveform, or by utilizing two or more geographically separated direction finders and triangulation techniques. The waveforms of the signals received by the direction finder are analyzed to determine whether the discharge is ground stroke or another type of discharge, or background noise. Further circuitry can be used to distinguish between various types of ground strokes, such as first strokes or subsequent strokes in a flash.