Abstract: A lightning ranging device which utilizes two frequencies in the field generated by a lightning discharge to determine range. The relative amplitudes of the outputs from two tuned receiver channels varies with distance from the lightning stroke. A two-dimensioned look-up table with two inputs and one output can be utilized to output the range. The original ratio of the amplitudes of the two frequencies can be determined empirically from experimental data and amplification factors on the two frequency channels are pre-set at different levels to compensate for this difference in the original energy level.

Abstract: A hand-held electronic apparatus for the detection and ranging of lightning strikes wherein radio frequency signals from lightning activity are filtered to allow selected low frequency emissions to be compared with standard voltages in order to activate light emitting diodes which correspond to distances to lightning activity: 0-10 miles, 10-20 miles, etc. The device only the electrostatic field component of the radio signals from lightning activity. The electrostatic component typically dominates over the electromagnetic component at comparatively short distances of 40 miles or less.