A statistical simulation of ground‐wave atmospherics generated by lightning return strokes

Abstract

A statistical model of lightning return strokes was used in a simulation program to determine the statistical properties of the atmospherics generated. Although the highly simplified Bruce‐Golde model of the return stroke was used, the results of this study compare well with recent experimental investigations. Statistical data were obtained for the α, β, and γ parameters of the Bruce‐Golde model which show that the variance of these parameters is too large to allow characterization by a single set of parameter values. The simulation program developed provides a simple means of evaluating the statistical effects of such factors as receiver bandwidth, changes in the nature of the return strokes, or propagation conditions which would be very difficult to evaluate either analytically or experimentally. Two examples of the application of the simulation program are given, the first of which illustrates the importance of the ground‐wave correction factor in determining the peak value of the electric field waveform. The second example demonstrates the effect of receiver bandwidth on the observed electric field waveform, and this simulation is equivalent to multiple observations, under different conditions, of exactly the same atmospherics at different propagation distances.

A probabilistic model for the initial peaks of ground wave atmospherics generated by lightning return strokes

“…Using (5) and expressing the results for f and S 2 in natural log units, new estimates of the mean peak electric field were calculated, and these are also given in The mean values of the peak electric field are plotted in Figure 1 along with the resulting analytical approximation which will be discussed below. It is interesting to note that if the curvature of the earth is neglected (by using (A4) instead of (A1) in the previous study [Lefferts, 1978] ), the mean value of the peak electric field at 500 km increases from 0.996 to 1.33 V/m (the circled point in Figure 1). From the position of this point in Figure 1 it would probably be sufficient to use a straight line to plot the results if the sphericity of the earth could be neglected.…”

“…It can be shown that the wave form of the atmospheric received at a distance r is [Lefferts, 1972[Lefferts, , 1978…”