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Development of an automatic procedure to estimate the reflection height of tweek atmospherics
Earth, Planets and Space volume 60, pages837–843(2008)
This paper presents an automated procedure to estimate apparent reflection height h (from the cutoff frequency for the first waveguide mode, fc), horizontal propagation distance d, and propagation time Tg of tweek atmospherics. Tweek data recorded at the Kagoshima Observatory (31.48°N, 130.72°E), Japan, were used to evaluate the procedure by comparing the results estimated by the automatic method to those read manually by an operator. The two types of results showed differences (automatic–manual) of +0.58 km, −9.9 Hz, and +3058.9 km for mean h, fc, and d, respectively. The difference in h(fc) was less than the resolution of the fast Fourier transform used to obtain the tweek spectra. These comparisons indicate that the automatic estimation procedure of tweek parameters developed in this paper performs well and is a useful tool for studying long-term height variations of the ionospheric D and lower E regions using very low frequency (VLF) and extremely low frequency (ELF) records observed in Japan over the past 30 years.
Bickel, J. E., J. A. Ferguson, and G. V. Stanley, Experimental observation of magnetic field effects on VLF propagation at night, Radio Sci., 5, 19, 1970.
Christian, H. J., R. J. Blakeslee, D. J. Bocchippio, W. L. Boeck, D. E. Buechler, K. T. Driscoll, S. J. Goodman, J. M. Hall, W. J. Koshak, D. M. Mach, and M. F. Stewart, Global frequency and distribution of lightnings as observed from space by the Optical Transient Detector, J. Geophys. Res., 108, ACL4–1–ACL4–15, 2003.
Davies, K., Ionospheric Radio Waves, Waltham, MA: Blaisdell, 1969.
Ferencz, O. E., Short impulse propagation in waveguides, Hiradastechnika “Communications”, LIX, 6, 2–6, 2004.
Ferencz, O. E., Cs. Ferencz, P. Steinbach, J. Lichtenberger, D. Hamar, M. Parrot, F. Lefeuvre, and J.-J. Berthelier, The effect of subiono-spheric propagation on whistlers recorded by the DEMETER satellite—observation and modeling, Ann. Geophys., 25, 1103–1112, 2007.
Hayakawa, M., K. Ohta, and K. Baba, Wave characteristics of tweek atmospherics deduced from the direction-finding measurement and theoretical interpretation, J. Geophys. Res., 99, 10733–10743, 1994.
Hayakawa, M., K. Ohta, S. Shimakura, and K. Baba, Recent findings on VLF/ELF sferics, J. Atmos. Terr. Phys., 57, 467–477, 1995.
Holdsworth, D. A., R. Vuthaluru, I. M. Reid, and R. A. Vincent, Differential absorption measurements of mesospheric and lower thermospheric electron densities using the Buckland Park MF radar, J. Atmos. Terr. Phys., 64, 2029–2042, 2002.
Lynn, K. J. and J. Crouchley, Night-time sferic propagation at frequencies below 10 kHz, Aust. J. Phys., 20, 101–108, 1967.
Maeda, K.-I., Study on electron density profile in the lower ionosphere, J. Geomag. Geoelectr., 23, 133–159, 1971.
Ohya, H., M. Nishino, Y. Murayama, and K. Igarashi, Equivalent electron densities at reflection heights of tweek atmospherics in the low-middle latitude D-region ionosphere, Earth Planets Space, 55, 627–635, 2003.
Ohya, H., M. Nishino, Y. Murayama, K. Igarashi, and A. Saito, Using tweek atmospherics to measure the response of the low-middle latitude D-region ionosphere to a magnetic storm, J. Atmos. Solar-Terr. Phys., 68, 697–709, 2006.
Outsu, J., Numerical study of tweeks based on waveguide mode theory, Proc. Res. Inst. Atmos., Nagoya University, 7, 58–71, 1960.
Shvets, A. V. and M. Hayakawa, Polarization effects for tweek propagation, J. Atmos. Solar-Terr. Phys., 60, 461–469, 1998.
Thomas, L. and M. D. Harrison, The electron density distributions in the D-region during the night and pre-sunrise period, J. Atmos. Terr. Phys., 32, 1–14, 1970.
Thomson, N. R., Experimental daytime VLF ionospheric parameters, J. Atmos. Terr. Phys., 55, 173–184, 1993.
Tohmatsu, T., Compendium of Aeronomy (translated and revised by T. Ogawa), Terra Scientific Pub. and Kluwer, 1990.
Yamashita, M., Propagation of tweek atmospherics, J. Atmos. Terr. Physics, 40, 151–153, 1978.
Wait, J. R., Electromagnetic Waves in Stratified Media, Pergamon, New York, 1972.
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Ohya, H., Shiokawa, K. & Miyoshi, Y. Development of an automatic procedure to estimate the reflection height of tweek atmospherics. Earth Planet Sp 60, 837–843 (2008) doi:10.1186/BF03352835
- Tweek atmospherics
- reflection height
- D-region ionosphere
- low latitudes