Ground-conductivity determinations at low radio frequencies by an analysis of the sferic signatures of thunderstorms

A technique is described for determining the conductivity of the ground at low frequencies with the aid of sferic pulses from thunderstorms. The paper is illustrated with an actual conductivity determination, and the detailed comparison of waveforms predicted theoretically with those observed experimentally indicates that an effective value of conductivity can be measured to a precision of one or two significant figures. The results of the analysis indicate application of both experimental and analytic techniques to other propagation studies, such as the evaluation of the reflection and transmission properties of the lower ionosphere.