Download or read book Propagation Effects of Very Low Frequency Radio Waves written by Sandip K. Chakrabarti and published by American Inst. of Physics. This book was released on 2010-11-23 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Studies of the propagation of Very Low Frequency (VLF) radio waves through the earth-ionospheric waveguide are being done for a long time. However, only recently it is being recognized that the amplitude and phase variations, especially the disturbances of the signal could be used to study varied effects such as solar flares, gamma ray bursts, soft gamma ray repeaters, seismic activities apart from the usual studies of tweeks, lighting induced electron precipitation etc. This conference, for the first time, focus the future of the subject in light of these new developments.
Download or read book An Investigation of the Modal Interference of Very low frequency Radio Waves written by F. J. RHOADS and published by . This book was released on 1965 with total page 65 pages. Available in PDF, EPUB and Kindle. Book excerpt: A very-low-frequency (vlf) radio-wave propagation experiment has been designed to study modal interference effects and the extent of agreement with theoretical results obtained previously. The experimental data are the field strengths of the vlf transmissions from the U.S. Navy transmitting stations NPM and Haiku in Hawaii and NPG near Seattle, Washington. These data were recorded aboard an aircraft while in flight between California, Guam, and Japan, and also at a field site near Washington, D.C. During the experiment, NPM transmitted for various periods on 16.6, 19.8, 22.3, 24.0, and 26.1 kc/s. The Haiku transmissions were on 16.6 and 19.8 kc/s, while NPG was on 18.6 kc/s continuously. The experimental field-strength-versus-distance graphs show considerable modal interference and very good agreement with the theoretical results for the isotropic case. For frequencies above 20 kc/s the experimental data indicate the existence of at least the first three modes for propagation to the west and to the east, out to distances greater than 3 megameters. The data at 19.8 kc/s, however, indicate first-three-mode effects for propagation to the east but only two modes to the west. The fading of the field strengths at Washington, D.C., during sunrise was frequently greater than 20 db. The depth of the fades, in general, increased with frequency, whereas their time of occurrence was relatively independent of frequency over the range of 19.8 to 26.1 kc/s. (Author).
Download or read book A Survey and Bibliography of Recent Research in the Propagation of VLF Radio Waves written by James R. Wait and published by . This book was released on 1960 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Propagation of Radio Waves at Frequencies below 300 Kc s written by W. T. Blackband and published by Elsevier. This book was released on 2014-06-28 with total page 493 pages. Available in PDF, EPUB and Kindle. Book excerpt: Propagation of Radio Waves at Frequencies Below 300 KC/S covers the proceedings of the Seventh Meeting at the AGARD Ionospheric Research Committee, held in Munich, Germany on September 17-21, 1962. This book is organized into eight parts encompassing 32 chapters. The first parts deal with research studies concerning the electron density distribution and some properties of the lower ionosphere, as well as the effect of D-layer irregularities on radio wave propagation. The next parts explore the low frequency propagation in the lower ionosphere, the measurement of oblique incidence, and the statistical frequency spectrum of radio noise below 300 kc/s. The remaining chapters discuss the diurnal changes, the statistical prediction, the mode theory, and the propagation of very and extremely low frequency radio waves in the ionosphere. These chapters also examine the Earth resonance. This book will prove useful to astronomers, astrophysicists, and space scientists.
Download or read book The Propagation Characteristics of Very Low Frequency Radio Waves written by George Washington Frey and published by . This book was released on 1959 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Terrestrial Propagation of Long Electromagnetic Waves written by Janis Galejs and published by Elsevier. This book was released on 2013-10-22 with total page 378 pages. Available in PDF, EPUB and Kindle. Book excerpt: Terrestrial Propagation of Long Electromagnetic Waves deals with the propagation of long electromagnetic waves confined principally to the shell between the earth and the ionosphere, known as the terrestrial waveguide. The discussion is limited to steady-state solutions in a waveguide that is uniform in the direction of propagation. Wave propagation is characterized almost exclusively by mode theory. The mathematics are developed only for sources at the ground surface or within the waveguide, including artificial sources as well as lightning discharges. This volume is comprised of nine chapters and begins with an introduction to the fundamental concepts of wave propagation in a planar and curved isotropic waveguide. A number of examples are presented to illustrate the effects of an anisotropic ionosphere. The basic equations are summarized and plane-wave reflection from a dielectric interface is considered, along with the superposition of two obliquely incident plane waves. The properties of waveguide boundaries are implicitly represented by Fresnel reflection coefficients. Subsequent chapters focus on boundaries of the terrestrial guide; lightning discharges as a natural source of extremely-low-frequency and very-low-frequency radiation; and the mode theory for waves in an isotropic spherical shell. This book will be a useful resource for students and practitioners of physics.
Download or read book The Transequatorial Propagation of Very Low Frequency Radiowaves written by Floyd Perry Snyder and published by . This book was released on 1980 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study reports on observations of dawn/dusk transition fading of very low frequency radiowaves on a long, transequatorial northeasterly propagation path. A mode conversion model is developed and numerical modeling results are presented for transition fading on long transequatorial paths, both northeasterly and southwesterly. From these results the following general conclusions are drawn: (a) Anomalous transequatorial transition fading is not observed for the northeasterly propagation path. The transition fading data support completely the mode conversion model of transition fading developed by Crombie. (b) The transequatorial sunrise transition reported in the literature as anomalous is completely explained by correctly allowing for variations of the geomagnetic field along the path. The geomagnetic field influences the nighttime modal parameters to such an extent for the southwesterly path considered that the approximate WKB method of mode summation cannot be employed. (c) Careful application of model techniques appears to be capable of describing all LF and VLF propagation in the earth-ionosphere waveguide, provided the effect of the earth's magnetic field is properly included at night. However, an improved model of the ionosphere at altitudes below 100 km is desired. (Author).
Download or read book Radiowave Propagation written by Curt Levis and published by John Wiley & Sons. This book was released on 2010-06-01 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt: An accessible student-oriented approach to radiowave propagation Propagation-the process whereby a signal is conveyed between transmitter and receiver-has a profound influence on communication systems design. Radiowave Propagation provides an overview of the physical mechanisms that govern electromagnetic wave propagation in the Earth's troposphere and ionosphere. Developed in conjunction with a graduate-level wave propagation course at The Ohio State University, this text offers a balance of physical and empirical models to provide basic physical insight as well as practical methods for system design. Beginning with discussions of propagation media properties, plane waves, and antenna and system concepts, successive chapters consider the most important wave propagation mechanisms for frequencies ranging from LF up to the millimeter wave range, including: Direct line-of-sight propagation through the atmosphere Rain attenuation The basic theory of reflection and refraction at material interfaces and in the Earth's atmosphere Reflection, refraction, and diffraction analysis in microwave link design for a specified terrain profile Empirical path loss models for point-to-point ground links Statistical fading models Standard techniques for prediction of ground wave propagation Ionospheric propagation, with emphasis on the skywave mechanism at MF and HF and on ionospheric perturbations for Earth-space links at VHF and higher frequencies A survey of other propagation mechanisms, including tropospheric scatter, meteor scatter, and propagation effects on GPS systems Radiowave Propagation incorporates fundamental materials to help senior undergraduate and graduate engineering students review and strengthen electromagnetic physics skills as well as the most current empirical methods recommended by the International Telecommunication Union. This book can also serve as a valuable teaching and reference text for engineers working with wireless communication, radar, or remote sensing systems.
Download or read book Theory of Propagation of Low Frequency Terrestrial Radio Waves written by J. Ralph Johler and published by . This book was released on 1967 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Propagation of Very Low Frequency Radio Waves Between the Lower Ionosphere and the Ground written by Raymond Norman Lindsay and published by . This book was released on 1974 with total page 330 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Long Range Propagation of Low Frequency Radio Waves Between the Earth and the Ionosphere written by J Shmoys and published by Andesite Press. This book was released on 2015-08-08 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Download or read book The Propagation of Very Low Frequency Radio Waves with Special Reference to the Omega Navigation System written by K. E. Mowforth and published by . This book was released on 1982 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Propagation of Radio Waves of Very Low Frequency written by William Cranna Bain and published by . This book was released on 1951 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book ELF VLF Radio Wave Propagation written by J.A. Holtet and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 409 pages. Available in PDF, EPUB and Kindle. Book excerpt: This volume is based on lectures and discussions presented at a NATO Advanced Study Institute on ELF and VLF Radio Wave Propagation, which was held in Norway April 1974. The study of propagation of electromagnetic waves with frequen cies below 100 kHz has long traditions in ionospheric physics. To-day, this frequency range is still of great importance, both to the physicist, who uses the waves as diagnostic tools to study the earth's environment and to the engineer who exploits the characteris tics of these waves to improve communications, navigation and timing systems. In recent years the active interest in the field has led to very rapid progress in the development of propagation theory as well as in the application of this theory to the solution of practical problems. The intention of the Organizing Committee for this Conference was to bring together theoreticians and experi mentalists working on the various aspects of wave propagation, in order to stimulate a fruitful discussion and exchange of ideas.
Download or read book Ionospheric Radio Propagation written by Kenneth Davies and published by . This book was released on 1965 with total page 490 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Long Range Propagation of Low Frequency Radio Waves Between the Earth and the Ionosphere Scholar s Choice Edition written by J Shmoys and published by Scholar's Choice. This book was released on 2015-02-15 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: This work has been selected by scholars as being culturally important, and is part of the knowledge base of civilization as we know it. This work was reproduced from the original artifact, and remains as true to the original work as possible. Therefore, you will see the original copyright references, library stamps (as most of these works have been housed in our most important libraries around the world), and other notations in the work. This work is in the public domain in the United States of America, and possibly other nations. Within the United States, you may freely copy and distribute this work, as no entity (individual or corporate) has a copyright on the body of the work.As a reproduction of a historical artifact, this work may contain missing or blurred pages, poor pictures, errant marks, etc. Scholars believe, and we concur, that this work is important enough to be preserved, reproduced, and made generally available to the public. We appreciate your support of the preservation process, and thank you for being an important part of keeping this knowledge alive and relevant.
Download or read book ELF and VLF Electromagnetic Field Effects written by Michael Persinger and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt: Recent emphasis upon the importance of the physical environment has made science and the public even more cog nizant of the many components of the biosphere. While much attention has been given to ionizing electromagnetic stimuli which causes blatant and unalterable changes in biological systems, relatively little research has been concerned with those electromagnetic signals whose frequencies overlap with time-varying processes in living organisms. Extremely low frequency (ELF) electromagnetic fields can occur as waves between about I Hz to 100 Hz or as short pulses within this range of very low frequency (VLF) and higher frequency sources. The natural occurrence of ELF signals is associated with weather changes, solar disturbances and geophysical ionospheric perturbations. Man-made sources have also been reported. Certain physical properties of ELF signals make them excellent candidates for biologically important stimuli. Unlike many other weather components, ELF signals have the capacity to penetrate structures which house living organ isms. ELF wave configurations allow long distance propaga tional capacities without appreciable attenuation of inten sity, thus making them antecedent stimuli to approaching weather changes. Most importantly, ELF signals exhibit the frequencies and wave forms of bio-electrical events that occur within the brain and body. Thus resonance inter actions between animal and nature become attractive possi bilities.
