Lightning amplitude spectra in the interval from 100 kHz to 20 MHz

The electric radiation fields produced by lightning return strokes, stepped leaders, and intracloud discharge processes have been Fourier-analyzed to determine amplitude spectra for these processes from about 100 kHz to 20 MHz. The fields were recorded under conditions where the lightning locations were known and where the field propagation from the lightning sources to the recording site was entirely over salt water. The spectra for return strokes show an f−1 frequency dependence from 100 kHz to 2 MHz, an f−2 dependence between 2 and 10 MHz, and an f−5 decrease above 10 MHz. In the 1 to 20 MHz range, the spectra of the initial fast transition in return strokes, the initial fast-rising portion of leader steps and the fast transitions in positive intracloud pulses are surprisingly similar.

[1]  E. Philip Krider,et al.  Regular radiation field pulses produced by intracloud lightning discharges , 1975 .

[2]  J. Wait,et al.  Curves for ground wave propagation over mixed land and sea paths , 1963 .

[3]  Martin A. Uman,et al.  The RF spectra of first and subsequent lightning return strokes in the 1‐ to 200‐km range , 1980 .

[4]  L. L. Oh.  Measured and Calculated Spectral Amplitude Distribution of Lightning Sferics , 1969 .

[5]  E. Krider,et al.  Lightning Direction-Finding Systems for Forest Fire Detection , 1980 .

[6]  E. Philip Krider,et al.  The electric fields produced by lightning stepped leaders , 1977 .

[7]  E. Philip Krider,et al.  The radiation field wave forms produced by intracloud lightning discharge processes , 1979 .

[8]  D. Barrick.  Theory of HF and VHF Propagation Across the Rough Sea, 2, Application to HF and VHF Propagation Above the Sea , 1971 .

[9]  Martin A. Uman,et al.  Effects of 200 km propagation on Florida lightning return stroke electric fields , 1976 .

[10]  W. L. Taylor.  Radiation field characteristics of lightning discharges in the band 1 kc/s to 100 kc/s , 1963 .

[11]  E. Philip Krider,et al.  The fine structure of lightning return stroke wave forms , 1978 .

[12]  Donald E. Barrick,et al.  Theory of HF and VHF Propagation Across the Rough Sea, 1, The Effective Surface Impedance for a Slightly Rough Highly Conducting Medium at Grazing Incidence , 1971 .

[13]  James R. Wait.  Propagation of electromagnetic pulses in terrestrial waveguides , 1965 .

[14]  Clayborne Taylor.  External Interaction of the Nuclear EMP with Aircraft and Missiles , 1978, IEEE Transactions on Electromagnetic Compatibility.

[15]  E. Philip Krider,et al.  Submicrosecond risetimes in lightning return-stroke fields , 1980 .

[16]  A. Kimpara.  ELECTROMAGNETIC ENERGY RADIATED FROM LIGHTNING , 1964 .

[17]  J. C. Corbin.  Protection/hardening of aircraft electronic systems against the indirect effects of lightning , 1979 .

[18]  E. Philip Krider,et al.  Radiation field wave forms produced by lightning stepped leaders , 1975 .

[19]  Richard F. Hess.  Properties of Induced Transients Associated with EM Fields Produced by Lightning or Other Relatively Slow Rise-Time EMP , 1978, 1978 IEEE International Symposium on Electromagnetic Compatibility.