Measured Spectral Amplitude of Lightning Sferics in the HF, VHF, and UHF Bands

An experimental study was carried out to measure the spectral amplitude of lightning sferics at 22.5 MHz, 225 MHz, and 2.25 GHz. This effort included the detection, storage, and analysis of RF emission data to determine accurately the relative electric-field strength produced by the lightning associated with a typical local thunderstorm. These measured spectral amplitudes are normalized and plotted relative to similar data from other investigators. These data support a l/f2 to 11f3 slope for sferics at frequencies above the HF range.