COMPARATIVE ANALYSIS OF METHODS OF EVALUATING THE LOWER IONOSPHERE PARAMETERS BY TWEEK ATMOSPHERICS

DOI: https://doi.org/10.15407/rpra21.04.270

A. P. Krivonos, A. V. Shvets

Abstract


PACS numbers: 94.20.wc, 94.20.de 

Purpose: A comparative analysis of the phase and frequency methods for determining the Earth-ionosphere effective waveguide heights for the basic and higher types of normal waves (modes) and distance to the source of radiation – lightning – has been made by analyzing pulse signals in the ELF-VLF range – tweek-atmospherics (tweeks).

Design/methodology/approach: To test the methods in computer simulations, the tweeks waveforms were synthesized for the Earth-ionosphere waveguide model with the exponential conductivity profile of the lower ionosphere. The calculations were made for a 20-40 dB signal/noise ratio.

Findings: The error of the frequency method of determining the effective height of the waveguide for different waveguide modes was less than 0.5 %. The error of the phase method for determining the effective height of the waveguide was less than 0.8 %. Errors in determining the distance to the lightning was less than 1 % for the phase method, and less than 5 % for the frequency method for the source ranges 1000-3000 km.

Conclusions: The analysis results have showed the accuracy of the frequency and phase methods being practically the same within distances of 1000-3000 km. For distances less than 1000 km, the phase method shows a more accurate evaluation of the range, so the combination of the two methods can be used to improve estimating the tweek’s propagation path parameters.

Key words: lightning location, diagnostics of the lower ionosphere, ELF-VLF radio waves, tweek-atmospherics

Manuscript submitted 12.10.2016

Radio phys. radio astron. 2016, 21(4): 270-278

REFERENCES

1. WAIT, J. R., 1962. Electromagnetic Waves in Stratified Media. Oxford, England: Pergamon Press.

2. HUGHES, H. G., GALLENBERGER, R. J. and PAPPERT,R. A., 1974. Evaluation of nighttime exponential ionospheric models using VLF atmospherics. Radio Sci. vol. 9, no. 12, pp. 1109–1116. DOI: https://doi.org/10.1029/RS009i012p01109

3. CUMMER, S. A., INAN, U. S. and BELL, T. F., 1998.Ionospheric D-region remote sensing using VLF radio atmospherics. Radio Sci. vol. 33, no. 6, pp. 1781–1792.DOI: https://doi.org/10.1029/98RS02381

4. CHENG, Z. and CUMMER, S. A., 2005. Broadband VLF measurements of lightning-induced ionospheric perturbations. Geophys. Res. Lett. vol. 32, is. 8, id. L08804. DOI: https://doi.org/10.1029/2004GL022187

5. CHENG, Z., CUMMER, S. A., SU, H.-T. and HSU, R.-R., 2007. Broadband very low frequency measurement of D region ionospheric perturbations caused by lightning electromagnetic pulses. J. Geophys. Res. vol. 112, is. A6,id. A06318. DOI: https://doi.org/10.1029/2006JA011840

6. SHAO, X.-M., LAY, E. H. and JACOBSON, A. R., 2013. Reduction of electron density in the night-time lower ionosphere in response to a thunderstorm. Nature Geosci. vol. 6, no. 1, pp. 29–33. DOI: https://doi.org/10.1038/ngeo1668

7. BURTON, E. T. and BOARDMAN, E. M., 1933. Audio frequency atmospherics. Proc. IRE. vol. 21, is. 10,pp. 1476–1494. DOI: https://doi.org/10.1109/JRPROC.1933.227485

8. BARKHAUSEN, H., 1930. Whistling tones from the Earth. Proc. IRE. vol. 18. is. 7, pp. 1155–1159. DOI: https://doi.org/10.1109/JRPROC.1930.222122

9. POTTER, R. K., 1951. Analysis of audio-frequency atmospherics. Proc. IRE. vol. 39, is. 9. pp. 1067–1069. DOI: https://doi.org/10.1109/JRPROC.1951.273750

10. OHYA, H., SHIOKAWA, K. and MIYOSHI, Y., 2008. Development of an automatic procedure to estimate thereflection height of tweek atmospherics. Earth Planets Space. vol. 60, is. 8, pp. 837–843. DOI: https://doi.org/10.1186/BF03352835

11. IWAI, A., KASHIWAGI, M., NISHINO, M. and SATOH.M., 1979. Triangulation direction finding networkfor fixing the sources of atmospherics. Proc. Res. Inst. Atmos. Nagoya Univ. vol. 26, pp. 1–16.

12. RODGER, C. J., BRUNDELL, J. B. and DOWDEN, R. L., 2005. Location accuracy of VLF World Wide Lightning Location (WWLL) network: Post-algorithm upgrade. Ann.Geophys. vol. 23, is. 2, pp. 277–290. DOI: https://doi.org/10.5194/angeo-23-277-2005

13. OUTSU, J., 1960. Numerical study of tweeks based on waveguide mode theory. Proc. Res. Inst. Atmos. Nagoya Univ. vol. 7, pp. 58–71.

14. RAFALSKY, V. A., SHVETS, A. V. and HAYAKAWA, M., 1995. One-site distance-finding technique forlocating lightning discharges. J. Atmos. Terr. Phys. vol. 57,is. 11, pp. 1255–1261. DOI: https://doi.org/10.1016/0021-9169(95)00011-P

16. WAIT, J. R. and SPIES, K. P., 1964. Characteristics of the earth-ionosphere waveguide for VLF radio waves. In: NBS Technical Note 300. Washington, DC: U.S. Department of Commerce, National Bureau of Standards.DOI: https://doi.org/10.6028/nbs.tn.300

17. GREIFINGER, C. and GREIFINGER, P., 1978. Approximate method for determining ELF eigenvalues in the earth-ionosphere waveguide. Radio Sci. vol. 13, no. 5, pp. 831-837. DOI: https://doi.org/10.1029/RS013i005p00831

18. PORRAT, D., BANNISTER, P. R. and FRASERSMITH, A. C., 2001. Modal phenomena in the natural electromagnetic spectrum below 5 kHz. Radio Sci. vol. 36, no 3, pp. 499–506. DOI: https://doi.org/10.1029/2000RS002506


Keywords


lightning location; diagnostics of the lower ionosphere; ELF-VLF radio waves; tweek-atmospherics

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