Download or read book Historical Overview of HF Ionospheric Modification Research written by William E. Gordon and published by . This book was released on 1990 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt: Radio waves have inadvertently modified the Earth's ionosphere since the Luxembourg observations of Tellegen in 1933 and perhaps since Marconi in 1901. The history of ionospheric modification by radio waves is reviewed, beginning with Marconi, describing the Luxembourg effect and its explanations, and its early use to deduce the properties of the lower ionosphere in the 1930s. 'ne measurements became more sophisticated in the 1950s, leading to the call for high-power high-frequency modification experiments in the upper ionosphere. Beginning in 1970, radio facilities became available of sufficient powers to induce changes in the ionospheric plasma detectable by a wide array of diagnostic instruments and techniques. A summary of these effects is presented based upon work up to 1990. These studies were originally motivated as a means of better understanding the natural ionosphere using a weak perturbational approach. However, a rich spectrum of nonlinear wave-plasma interactions was quickly discovered and ionospheric modification research became strongly motivated by issues in basic plasma physics. The ionosphere and near-Earth space are now exploited as an exceptional plasma laboratory-without-walls for the study of fundamental plasma processes requiring large spatial or temporal scales. Here we present a brief overview of these processes and phenomena, illustrated using results obtained from the Arecibo ionospheric modification facilities. The lessons learned and phenomena explored thus far offer many opportunities for controlling the ionospheric environment critical to many civilian and military telecommunications systems, both to disrupt systems normally operational and to create new propagation paths otherwise unavailable.
Download or read book Space Physics and Aeronomy Ionosphere Dynamics and Applications written by Chao Huang and published by John Wiley & Sons. This book was released on 2021-05-11 with total page 47 pages. Available in PDF, EPUB and Kindle. Book excerpt: A comprehensive review of global ionospheric research from the polar caps to equatorial regions It's more than a century since scientists first identified the ionosphere, the layer of the Earth’s upper atmosphere that is ionized by solar and cosmic radiation. Our understanding of this dynamic part of the near-Earth space environment has greatly advanced in recent years thanks to new observational technologies, improved numerical models, and powerful computing capabilities. Ionosphere Dynamics and Applications provides a comprehensive overview of historic developments, recent advances, and future directions in ionospheric research. Volume highlights include: Behavior of the ionosphere in different regions from the poles to the equator Distinct characteristics of the high-, mid-, and low-latitude ionosphere Observational results from ground- and space-based instruments Ionospheric impacts on radio signals and satellite operations How earthquakes and tsunamis on Earth cause disturbances in the ionosphere The American Geophysical Union promotes discovery in Earth and space science for the benefit of humanity. Its publications disseminate scientific knowledge and provide resources for researchers, students, and professionals. Find out more about the Space Physics and Aeronomy collection in this Q&A with the Editors in Chief
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1991 with total page 920 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1989 with total page 1148 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Soviet Ionospheric Modification Research written by and published by . This book was released on 1988 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modeling of HF Propagation and Heating in the Ionosphere written by and published by . This book was released on 1992 with total page 116 pages. Available in PDF, EPUB and Kindle. Book excerpt: The purpose of the program of research reported here is to develop and demonstrate a realistic numerical model for self-consistent ionospheric propagation and heating of powerful frequency (HF) waves by conjoining existing, separate numerical models for high frequency wave propagation and ionospheric transport. A comprehensive numerical implementation of plasma geometric optics has been enhanced and adapted to the problem of self-consistent ionospheric propagation of high power, high frequency radar signals. The emphasis in this work is on the realistic and rigorous description of the propagation waves so that geometric and spectral characteristics of nonlinear ionospheric effects can be predicted in detail. The plasma geometric optics code has been used in conjunction with an ionospheric transport code to determine self-consistently the HF radiation field and quasilinear modifications of ionospheric plasma properties due to ohmic dissipation of the HF radiation. This allows detailed study of nonlinear phenomena such as beam self-focusing formation of large-scale density cavities and striations, and induced wave ducting. Overviews of the theory underlying the existing models of radiation propagation and ohmic power deposition are given, and enhancements to these models are described. New results achieved using the enhanced models are shown and the treatment of a self-consistent propagation and heating problem is presented. Ray Tracing, Ionospheric Modification, Over-the-Horizon Radar Propagation, Ionospheric HF propagation, HF Heating of Ionosphere, Ionospheric Clutter.
Download or read book A Review of Some Ionospheric Studies Based on a High frequency Doppler Technique written by D. M. Baker and published by . This book was released on 1968 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report contains a review of the work done on frequency fluctuations of ionospheric radio echoes on high frequencies. The historical aspects are briefly discussed to show the development of research on solar flare effects and the motion of ionospheric irregularities. The recording program over the past 7 years and the equipment modifications involved are discussed. This is followed by a brief review of the elementary theory underlying frequency fluctuations. In most of the report the mathematical equations are listed in tables rather than distributed throughout the text. Solar flare effects (called sudden frequency deviations) are used to determine the relaxation time of the ionosphere.
Download or read book IONOSPHERIC MODIFICATION BY HIGH POWER OBLIQUELY PROPAGATED HF RADIO WAVE TRANSMISSIONS PART 1 EXPERIMENTAL written by United States. Air Force Materiel Command and published by . This book was released on 1993 with total page 23 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ionospheric Modification by High power Radio Waves written by and published by . This book was released on 1981 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: Powerful, high-frequency radio waves have been used to temporarily modify the ionosphere. Thermal and parametric interactions have led to a diverse range of observed phenomena, including generation of density striations and artificial spread-F, enhancements of electron plasma waves, production of extrathermal electron fluxes and enhanced airglow, modification of the D-region temperature and densities, wideband signal attenuation, and self-focusing and scattering of the electromagnetic waves. The physics of ionospheric modification by high-power radio waves is reviewed in the context of our current theoretical understanding; disturbance generation mechanisms are qualitatively described. In addition, results of recent experiments are summarized in which ionospheric irregularities are generated and their evolution and decay processes investigated in detail. The effects and potential controlled applications of these HF ionospheric modifications for various RF systems studies are discussed. The C3I scientific community provides an important motivation for these ionospheric modification studies; their increased interaction and active participation in experimental design and interpretation are encouraged.
Download or read book Ionosphere New Perspectives written by Yann-Henri Chemin and published by BoD – Books on Demand. This book was released on 2023-06-21 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: The ionosphere is a layer of the Earth's atmosphere that extends from about 50 km to 1000 km above the Earth's surface. It is ionized by solar radiation, which creates ions and free electrons in the upper atmosphere. These ions and electrons reflect radio waves back to the Earth's surface, allowing long-distance radio communication as well as absorption of harmful solar radiation. Ionospheric conductivity monitoring assesses the state of the ionosphere and improves the accuracy of satellite communications. This book is organized into two sections on the influence and impact of transient or orbiting humanmade objects into the ionosphere and the monitoring and modeling of the temporal evolution of the ionosphere. The information presented will lead to a better understanding and forecasting of the ionosphere’s dynamic.
Download or read book Winter Waterfront Year round Use in Metropolitan Toronto written by Xenia Klinger and published by . This book was released on 1991 with total page 79 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Energy Research Abstracts written by and published by . This book was released on 1990 with total page 852 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Results of a High Power Oblique Incidence High Frequency Ionospheric Modification Experiment written by Gary S. Sales and published by . This book was released on 1989 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Government Reports Annual Index written by and published by . This book was released on 1992 with total page 1128 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nuclear Science Abstracts written by and published by . This book was released on 1975-03 with total page 988 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Active Experiments in Space Past Present and Future written by Gian Luca Delzanno and published by Frontiers Media SA. This book was released on 2020-07-10 with total page 288 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Space Studies Board Annual Report 2013 written by National Research Council and published by National Academies Press. This book was released on 2014-04-09 with total page 83 pages. Available in PDF, EPUB and Kindle. Book excerpt: The original charter of the Space Science Board was established in June 1958, 3 months before the National Aeronautics and Space Administration (NASA) opened its doors. The Space Science Board and its successor, the Space Studies Board (SSB), have provided expert external and independent scientific and programmatic advice to NASA on a continuous basis from NASA's inception until the present. The SSB has also provided such advice to other executive branch agencies, including the National Oceanic and Atmospheric Administration (NOAA), the National Science Foundation (NSF), the U.S. Geological Survey (USGS), the Department of Defense, as well as to Congress. Space Studies Board Annual Report 2013 covers a message from the chair of the SSB, Charles F. Kennel. This report also explains the origins of the Space Science Board, how the Space Studies Board functions today, the SSB's collaboration with other National Research Council units, assures the quality of the SSB reports, acknowledges the audience and sponsors, and expresses the necessity to enhance the outreach and improve dissemination of SSB reports. This report will be relevant to a full range of government audiences in civilian space research - including NASA, NSF, NOAA, USGS, and the Department of Energy, as well members of the SSB, policy makers, and researchers.
