Browsing by Author "Shvets, Аleksandr V."

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Automatic Method for Monitoring the Lower Ionosphere and Lightning Location by Tweek-Atmospherics
(Університет прикладних наук Інхолланд, Голландія, 2018) Shvets, Аleksandr V.; Krivonos, Alexey P.; Serdiuk, Tetiana M.; Hayakawa, M.
ENG: A new real-time technique is proposed for automatic identification of tweek atmospherics, distance finding to lightning and estimating the effective heights of the lower ionosphere for the fundamental and higher order modes of the Earth-ionosphere waveguide. Effectiveness of the technique is demonstrated with the experimental records of atmospherics. Application of a clustering algorithm allowed us to reveal different patterns of variations of the lower ionosphere effective height along different propagations paths. The distance finding accuracy of our tweek method had been roughly estimated by a comparison with independent data from the Blitzortung.org lightning location network to be less than 100 km with standard deviation less than 200 km in the range of distances from 500 to 1400 km.
Estimating the Lower Ionosphere Height and Lightning Location Using Multimode "Tweek" Atmospherics
(Elsevier, 2014) Shvets, Аleksandr V.; Serdiuk, Tetiana M.; Gorishnyaya, Y. V.; Hobara, Y.; Hayakawa, M.
EN: There is proposed a new method of estimating the effective ionospheric height of the Earth-ionosphere waveguide and the propagation distance of tweek-atmospherics. It is based on the compensation of waveguide frequency dispersion of a tweek signal, which enables us to improve the accuracy of deducing the cutoff frequencies, especially in the presence of noise. An approach to solve the inverse problem is suggested that reduces the task of finding both the source range and the waveguide cutoff frequencies by using the multimode characteristics of tweeks to an issue of one-dimensional optimization. Based on the numerical modeling of multimode tweek-atmospherics in the Earth-ionosphere waveguide with exponential vertical conductivity profile of the lower ionosphere, it was shown that the accuracy of estimating the effective waveguide height by the new method is good as about 100-400. m for the first and higher order modes. It then allows us to estimate the parameters of vertical conductivity profile of the lower ionosphere for a wide range of source distances from a few hundred to a few thousand kilometers, as long as two or more tweek harmonics can be detected. Preliminary analysis of experimental tweek records show a decrease of the effective height with increasing the mode number, and the scale height of the exponential vertical conductivity profile for the isotropic lower ionosphere model is estimated to be in a range of 0.4-2.5. km. © 2013 .
Numerical Modeling of Multimode Tweek-Atmospherics in the Earth-Ionosphere Waveguide
(Дніпропетровський національний університет залізничного транспорту імені академіка В. Лазаряна, Дніпропетровськ, 2014) Serdyuk, Tatyana N.; Shvets, Аleksandr V.
EN: Actuality of the work. Information about the coordinates of lightning received in real time is important to assess the risk for different types of transport, power transmission and communication lines, gas and oil pipelines, protection of forests, open cast mining, industrial and port facilities. Accumulated for a long time data on the frequency of occurrence of lightning within the territory covered by the network can serve for geophysical and meteorological research, and for the purposes of ensuring safety in the design of industrial facilities and transport links. The US, a number of Western European countries, Japan, China and South Korea have national lightning detection networks ensuring the accuracy of the location of a few kilometers. This information is provided on a commercial basis. The lightning location network is based on numerous items of registration of electromagnetic radiation, equipped with fairly complicated synchronously operating equipment, and its implementation is technically difficult and expensive procedure. Alternative to the networks for many applications are single station locating systems based on the definition of the azimuth and distance to a source. However, they have much smaller precision of location determination than multi-position systems. Therefore, an actual task is to develop single-position location techniques that can increase the accuracy of determining the coordinates of lightning. The purpose of this paper is to analyze the accuracy of existing methods based on numerical modeling and development a new and improved method of single-site lightning location using ltweek-atmospherics - electromagnetic signals that represent the response of the natural Earth-ionosphere waveguide in the frequency range from 1 to 20 kHz to excitation by lightning discharges. As a result of this work methods of determining the distance to lightning are analyzed and a new method is proposed consisting in compensation of the waveguide dispersion in the signals, thus improving the accuracy of the estimates of distance to lightning in the range 100..3000 km and some ionospheric parameters, especially in the presence of noise.
A Technique for Automatic Monitoring the Lower Ionosphere and Lightning Location by Tweekatmospherics
(Guwahati: IJEAR Department of Physics Gauhati University, 2017) Shvets, Аleksandr V.; Krivonos, A. P.; Serdiuk, Tetiana M.; Hayakawa, M.
ENG: A new real-time technique is proposed for automatc identification of tweek atmospherics, distance finding to lightning and estimating the effective heights of the lower ionosphere for the fundamental and higher order modes of the Earth-ionosphere waveguide. Effectiveness of the technique is demonstrated with the experimental records of atmospherics. Application of a clustering algorithm allowed us to reveal different patterns of variations of the lower ionosphere effective height along different propagations paths. The distance finding accuracy of our tweek method had been roughly estimated by a comparison with independent data from the Blitzortung.org lightning location network to be less than 100 km with standard deviation less than 200 km in the range of distances from 500 to 1400 km.
Tomography Technique for Global Lightning Imaging from Ambient ELF Electromagnetic Noise
(Дніпропетровський національний університет залізничного транспорту ім. акад. В. Лазаряна, Дніпропетровськ, 2011) Shvets, Аleksandr V.; Serdyuk, Tatyana N.
EN: The article investigates tomography technique for global lightning imaging from ambient ELF electromagnetic noise.