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Frequency Analysis of Broadband Interferometer for Lightning Observations
Technical Paper
1999-01-2339
ISSN: 0148-7191, e-ISSN: 2688-3627
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English
Abstract
In a broadband interferometer technique, the discrete Fourier transform is used to analysis the whole frequency range of a lightning radiation pulse and after resolving the phase difference and incident angle, the direction of the electromagnetic source can be determined by averaging the angular position (azimuth and elevation) of all frequencies. We found that the method of averaging the angular position as proposed by previous authors has a disadvantage, that is a part of reconstructed lightning channel near the ground level often disappears due to higher frequencies are taken into account. The Fourier energy spectrum of broadband signal decreases along with increasing frequency, and frequencies having low energy spectrum contribute very small to the lightning reconstruction. For better reconstruction, a method of using a weighting function is proposed. The broadband frequencies that contribute very well to the reconstructed lightning channel should be amplified, otherwise the rest should be attenuated. By taking the cross power spectrum of broadband signals as the main consideration, we succeeded to map lightning discharge channels, especially at low elevation, in two dimensions with better reconstruction.
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Authors
Citation
Mardiana, R. and Kawasaki, Z., "Frequency Analysis of Broadband Interferometer for Lightning Observations," SAE Technical Paper 1999-01-2339, 1999, https://doi.org/10.4271/1999-01-2339.Also In
References
- Hayenga, C. O. Warwick J. W. Two-dimensional interferometric positions of VHF lightning sources J. Geophys. Res. 86 7451 7462 1981
- Mardiana, R. Ohta Y. Murakami M. Ushio T. Kawasaki Z. Matsuura K. A Broadband radio Interferometer for Observing Lightning Discharge Processes J. Atmosph. Electricity 18 111 117 1998
- Nanevictz, J.E. Vance E.F. Hamm J.M. Observation of lightning in the frequency and time domain, Lightning Electromagnetic New Mexico Hemisphere Pub. Corp. 191 210 1990
- Piersol, A.G. Time Delay Estimation Using Phase Data IEEE Transc. ASAP-29 3 June 1981
- Proctor, D. E A Hyperbolic System for Obtaining VHF Radio Pictures of Lightning J. Geophys. Res. 76 1478 1489 1971
- Shao, X.M. Holden D.N. Rhodes C.T. Broadband radio interferometry for lightning obesrvations Geophys. Res. Lett. 23 1917 1920 1996
- Stratton, J. A Electromagnetic Theory McGraw-Hill 1941
- Uman, M.A. The Lightning Discharge Academic San Diego, Calif. 1987
- Ushio, T. Kawasaki Z. Ohta Y. Matsuura K. Watanabe T. Liu X. Manufacture of broadband interferometer and observation of lightning discharges in China Scientific Meeting: Institute of Electrical Engineers of Japan, ED-97-118~149 155 160 1997
- Ushio, T. Kawasaki Z. Ohta Y. Matsuura K. Broadband interferometric measurement of rocket triggered lightning in Japan Geophys. Res. Lett. 24 2769 2772 1997
- Ushio, T. Kawasaki Z. Ohta Y. Matsuura K. Wireless Engineering Handbook Ohmsha 1964