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Rothkaehl, H.
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Rothkaehl, H.
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- PublicationOpen AccessIonospheric disturbances generated by different natural processes and by human activity in Earth plasma environment(2004)
; ; ; ; ; ; ; ; ;Rothkaehl, H.; Space Research Centre, Warsaw, Poland ;Izohkina, N.; Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagatio (IZMIRAN),Russian Academy of Sciences, Troitsk (Moscow Region), Russia ;Prutensky, N.; Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagatio (IZMIRAN),Russian Academy of Sciences, Troitsk (Moscow Region), Russia ;Pulinets, S.; Institute of Terrestrial Magnetism, Ionosphere and Radio Wave Propagatio (IZMIRAN),Russian Academy of Sciences, Troitsk (Moscow Region), Russia ;Parrot, M.; LPCE/CNRS, Orleans, France ;Lizunov, G.; Kyiv Shevchenko University, Ukraine ;Blecki, J.; Space Research Centre, Warsaw, Poland ;Stanislawska, I.; Space Research Centre, Warsaw, Poland; ; ; ; ; ; ; The magnetosphere-ionosphere-thermosphere subsystem is strongly coupled via the electric field, particle precipitation, heat flows and small scale interaction. Satellites in situ measurements and ground based complex diagnostics can provide comprehensive coverage of both time and geomagnetic place effects. Human activity also can perturb Earth s environment, but few are connected with controlled experiments in the ionosphere and are transient. Most of them are related to industrial activity and have increased in recent years. The most important power sources are broadcasting transmitters, power stations, power lines and heavy industry. At ionospheric altitude some disturbances and physical processes are related to seismic activity, thunderstorm activity and some global changes in the Earth environment such as ozone holes. Various natural and artificial indicators can affect satellite telecommunication quality. The aim of this presentation is to report progress in understanding the physical processes in the ionosphere described above and to assess the application of these considerations to the study of plasma effects on Earth-space and satellite-to-satellite communication.185 1289 - PublicationOpen AccessHF radio emissions as a tool of ionospheric plasma diagnostics(1996-08)
; ; ;Rothkaehl, H.; Space Research Centre, Polish Academy of Sciences, Warsaw, Poland ;Klos, Z.; Space Research Centre, Polish Academy of Sciences, Warsaw, Poland; The electromagnetic emission in the topside ionosphere has been investigated since the first satellites were located on the orbits. HF measurements can be used to diagnose the different electron plasma waves as well as the typical ionospheric parameters like f0F2. This paper presents the examples of measurements of the ionospheric RF radio noises in 0.1-10.0 MHz frequency range, which have been observed on the boards of the Intercosmos-19, Intercosmos-24, APEX satellites in the period 1979-1992, and the current experiment CORONAS.167 223 - PublicationOpen AccessAspects of HF radio propagation(2009-08)
; ; ; ; ; ; ; ; ; ; ; ; ; ; ; ;Warrington, E. M.; Department of Engineering, University of Leicester, UK ;Bourdillon, A.; IETR, Université de Rennes 1, France ;Benito, E.; Electromagnetism and Radar Department, Onera, Palaiseau, France ;Bianchi, C.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Monilie, J. P.; Electromagnetism and Radar Department, Onera, Palaiseau, France ;Muriuki, M.; Department of Engineering, University of Leicester, UK ;Pietrella, M.; Istituto Nazionale di Geofisica e Vulcanologia, Sezione Roma2, Roma, Italia ;Rannou, V.; Electromagnetism and Radar Department, Onera, Palaiseau, France ;Rothkaehl, H.; Space Research Centre PAS 00-716 Warsaw, Poland ;Saillant, S.; Electromagnetism and Radar Department, Onera, Palaiseau, France ;Sari, O.; Aselsan A.S., Macunkoy, Ankara, Turkey ;Stocker, A. J.; Department of Engineering, University of Leicester, UK ;Tulunay, E.; ODTÜ/METU, Department of Electrical and Electronics Engineering, Ankara, Turkey ;Tulunay, Y.; ODT /METU, Department of Aerospace Engineering, Ankara, Turkey ;Zaalov, N. Y.; Department of Engineering, University of Leicester, UK; ; ; ; ; ; ; ; ; ; ; ; ; ; The propagation characteristics of radio signals are important parameters to consider when designing and operating radio systems. From the point of view Working Group 2 of the COST 296 Action, interest lies with effects associated with propagation via the ionosphere of signals within the HF band. Several aspects are covered in this paper: a) The directions of arrival and times of flight of signals received over a path oriented along the trough have been examined and several types of propagation effects identified. Of particular note, combining the HF observations with satellite measurements has identified the presence of irregularities within the floor of the trough that result in propagation displaced from the great circle direction. An understanding of the propagation effects that result in deviations of the signal path from the great circle direction are of particular relevance to the operation of HF radiolocation systems. b) Inclusion of the results from the above mentioned measurements into a propagation model of the northerly ionosphere (i.e. those regions of the ionosphere located poleward of, and including, the mid-latitude trough)and the use of this model to predict the coverage expected from transmitters where the signals impinge on the northerly ionosphere. c) Development of inversion techniques enabling backscatter ionograms obtained by an HF radar to be used to estimate the ionospheric electron density profile. This development facilitates the operation of over the horizon HF radars by enhancing the frequency management aspects of the systems. d) Various propagation prediction techniques have been tested against measurements made over the trough path mentioned above, and also over a long-range path between Cyprus and the UK. e) The effect of changes in the levels of ionospheric disturbances on the operational availability at various data throughput rates has been examined for the trough path mentioned earlier. The topics covered in this paper are necessarily brief, and the reader is referred to full papers referenced herein on individual aspects.480 575