Download or read book Observation Analysis and Modeling of Ionospheric Total Electron Content TEC and Scintillation Effects written by and published by . This book was released on 1996 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many military systems used for communications, command and control, navigation, tracking, and surveillance depend on reliable and relatively noise free transmission of radiowave signals through the earth's ionosphere. These systems can be affected by both large scale features (> 1,000 km) and small scale structures (
Download or read book Further Investigations of Ionospheric Total Electron Content and Scintillation Effects on Transionospheric Radiowave Propagation written by United States. Air Force. Air Matériel Command and published by . This book was released on 1998 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of the ionosphere on numerous communication, navigation, and surveillance systems continue to be of Air Force concern. In this project, Northwest Research Associates (NWRA) is collaborating with researchers from Air Force Research Laboratory at Hanscom AFB and others to address these concerns in three broad areas. In the most advanced effort, operational code for running a gridded version of the WBMOD ionospheric scintillation model, called WBMGRID, with the full Scintillation Decision Aid (SCINDA) system was delivered to the 50th Weather Squadron (now the 55th Space Weather Squadron). The most extensive of the NWRA efforts involved careful use of two-frequency GPS receivers to measure ionospheric total electron content (TEC), which introduces range errors on operational GPS links. Central tasks in this effort included utilization of receivers at four operational sites of the Ionospheric Measuring System (IMS), continued development and refinement of the IMS employing a fifth receiver located at Hanscom, and assessment and analysis of the resulting data. The newest of the efforts goes beyond passive observation of ionospheric effects on radiowave systems to preparation for active experiments in the High Frequency Active Auroral Research Program (HAARP).
Download or read book Further Investigations of Ionospheric Total Electron Content and Scintillation Effects on Transionospheric Radiowave Propagation written by C. Charley Andreasen and published by . This book was released on 1998 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of the ionosphere on numerous communication, navigation, and surveillance systems continue to be of Air Force concern. In this project, Northwest Research Associates (NWRA) is collaborating with researchers from Air Force Research Laboratory at Hanscom AFB and others to address these concerns in three broad areas. In the most advanced effort, operational code for running a gridded version of the WBMOD ionospheric scintillation model, called WBMGRID, with the full Scintillation Decision Aid (SCINDA) system was delivered to the 50th Weather Squadron (now the 55th Space Weather Squadron). The most extensive of the NWRA efforts involved careful use of two-frequency GPS receivers to measure ionospheric total electron content (TEC), which introduces range errors on operational GPS links. Central tasks in this effort included utilization of receivers at four operational sites of the Ionospheric Measuring System (IMS), continued development and refinement of the IMS employing a fifth receiver located at Hanscom, and assessment and analysis of the resulting data. The newest of the efforts goes beyond passive observation of ionospheric effects on radiowave systems to preparation for active experiments in the High Frequency Active Auroral Research Program (HAARP).
Download or read book Total Electron Content and Scintillation Studies of the Ionosphere written by Jules Aarons and published by . This book was released on 1973 with total page 120 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analyze and Study Ionospheric Scintillation and Total Electron Content Variability Ionospheric Studies and TEC Variations written by Santimay Basu and published by . This book was released on 1981 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ionospheric scintillation analyses have been conducted on several fronts, and are discussed here in the light of: (1) recent observations, current theories, and coordinated studies of equatorial scintillations; (2) morphology and analytical formulas at high latitudes; (3) measurements associated with ionospheric heating. F-region irregularities are viewed from the concepts of localized origin of patches, in-situ spectral measurements, and coexistence of km- and m-scale irregularities. The dynamics of equatorial patch formation, motion, and decay are also discussed. Generation of irregularities during underdense heating was observed for the first time. Total electron content data have been utilized to derive the statistics of the variability of ionospheric time delay in the Mediterranean region for the current solar maximum period. The implications of the results on modern satellite ranging systems are discussed. (Author).
Download or read book Ionospheric Scintillations TEC and In situ Density Measurements at an Auroral Location in the European Sector written by Eileen MacKenzie and published by . This book was released on 1987 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The orbiting HiLat satellite launched in 1983 offered an opportunity for studying ionospheric scintillation parameters in relation to in-situ measurements of ionization density, drift velocity, field-aligned current, and particle precipitation during the sunspot minimum period. This report discusses results of a morphological study based on observations of scintillations and total electron content (TEC) at the auroral oval station at Tromso, Norway, during the period Dec 1983 - Oct 1985. The geometrical enhancement of scintillations observed during alignment of the propagation with the local magnetic L-shell is shown to be the most consistent and conspicuous feature of scintillations in the nighttime auroral oval. The dynamics of the spatial and temporal extent of this region are illustrated in the invariant latitude/magnetic local time grid. Steepening of phase spectral slope in the geometrical enhancement region is indicative of the presence of L-shell aligned sheet-like irregularities at long scale lengths. The seasonal variation of TEC determined from the differential Doppler measurements of HiLat transmissions is discussed in relation to the in-situ density measurements at 830 km. The results are also used to illustrate the dependence of ionospheric structure parameters on short-term variability of solar activity during the sunspot minimum period. This study provides an insight into the nature of magnetospheric coupling with the ionosphere at high latitudes.
Download or read book Analysis of Ionospheric Monitoring System IMS Total Electron Content TEC Data and Equatorial Phase scintillation Data written by James A. Secan and published by . This book was released on 1995 with total page 41 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ionospheric Radio written by Kenneth Davies and published by IET. This book was released on 1990 with total page 612 pages. Available in PDF, EPUB and Kindle. Book excerpt: This introductory text replaces two earlier publications (Davies 1965, 1969). Among the topics: characteristics of waves and plasma, the solar-terrestrial system, the Appleton formula, radio soundings of the ionosphere, morphology of the ionosphere, oblique propagation, importance of amplitude and phase, earth-space propagation. Annotation copyrighted by Book News, Inc., Portland, OR
Download or read book Modelling of Ionospheric Irregularities and Total Electron Content written by S. Basu and published by . This book was released on 1983 with total page 141 pages. Available in PDF, EPUB and Kindle. Book excerpt: F-region irregularities near the equator are viewed from the concept of the temporal structure of UHF scintillations and the electron content depletions associated with VHF, UHF and GHz scintillations. Near the equatorial anomaly crest, the solar cycle effect on GHz scintillation and the depolarization of VHF satellite signals are probed along with electron density irregularities using in-situ data coupled with VHF/GHJz scintillation. Occurrence of nighttime VHF scintillation in the Indian sector near the anomaly is addressed. In the midlatitude sector, coordinated incoherent scatter radar, total electron content and scintillation measurements are studied in the investigation of the generation of km-scale irregularities which spatial variability of total electron content is analyzed in the Mediterranean region. At high latitudes, in-situ measurements provide the opportunity for scintillation modelling which low-energy electron precipitation measurements have been correlated with scintillations/TEC in the auroral oval. The nature of ionospheric irregularities generated by high-power, high-frequency heating has also been investigated and shown to vary between two sites studied.
Download or read book Ionospheric Tomography written by Viacheslav E. Kunitsyn and published by Springer Science & Business Media. This book was released on 2003-05-13 with total page 282 pages. Available in PDF, EPUB and Kindle. Book excerpt: Authored by leading international researchers, this monograph introduces and reviews developed tomograhic methods for discovering 2D and 3D structures of the ionosphere, and discusses the experimental implementation of these methods. The detailed derivations and explanations make this book an excellent starting point for non-specialists.
Download or read book Ionospheric Electron Content and Radio Scintillations During Magnetospherically Quiet Periods in 1970 71 written by Gerald S. Hawkins and published by . This book was released on 1974 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Global Positioning System written by Bradford W. Parkinson and published by AIAA. This book was released on 1996 with total page 830 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effect of the Ionosphere on Space Systems and Communications written by and published by . This book was released on 1975 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book High Latitude Models Observations and Analysis of Ionospheric Scintillations written by Jules Aarons and published by . This book was released on 1973 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: In order to provide systems engineers with observations and analysis of the amplitude-fading of radio waves traversing the high latitude ionosphere, several different studies were performed. The concept was to develop descriptive and statistical models for the pattern of occurrence and amplitude of scintillations at high latitudes. Then, long terms observations from a limited number of sites could be linked to allow an assessment of the scintillation problem to communication, navigation, and detection systems in the VHF and UHF bands. This report discusses these studies in three chapters. In Chapter 1, general patterns of scintillation occurrence and intensity are presented in the descriptive model of the F-layer irregularities at high latitudes. This is followed in Chapter 2 by a graphical presentation of the data; that is, observations of the 136 MHz beacon of ATS-3. Chapter 3 organizes the observations into a useful format-the cumulative amplitude probability distribution function-for the engineer. A means of adjusting the observations for frequency dependence is provided.
Download or read book Model of Equatorial Scintillations from in Situ Measurements written by Sunanda Basu and published by . This book was released on 1976 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: In situ measurements of F-region irregularity amplitude and ambient electron density made by the retarding potential analyzer (RPA) on OGO-6 near perigee altitude of 400 km have been utilized to derive the variation of electron density deviation over the equatorial region. Based on these measured electron density deviations and other assumed model parameters, including a three-dimensional power-law form of irregularity spectrum of index 4, a model of equatorial scintillations is developed in the framework of diffraction theory. The percentage occurrence contours of estimated equatorial scintillations greater than or equal to 4.5 dB at 140 MHz during 1900 to 2300 LMT for the period November to December 1969 and 1970 have been derived. The model is found to depict a pronounced longitude variation with the scintillation belt width and percentage occurrence being maximum over the African sector. The latitude extent of the spatial scintillation belt narrows over the American sector without much decrease in the scintillation occurrence whereas over the Indian and Far Eastern sectors both the extent and the occurrence are found to decrease. The percentage occurrence of scintillations estimated from this model is found to be consistent with VHF scintillation measurements at Ghana, Huancayo, and Calcutta. In addition, the model was found to be in qualitative agreement with GHz observations at various longitudes made by the COMSAT group. The effect of varying model parameters on scintillation estimates at VHF, UHF and GHz are discussed. Implications of the observed longitudinal variation of scintillations on current theories of equatorial irregularity formation are indicated. (Author).
Download or read book Extreme Events in Geospace written by Natalia Buzulukova and published by Elsevier. This book was released on 2017-12-01 with total page 798 pages. Available in PDF, EPUB and Kindle. Book excerpt: Extreme Events in Geospace: Origins, Predictability, and Consequences helps deepen the understanding, description, and forecasting of the complex and inter-related phenomena of extreme space weather events. Composed of chapters written by representatives from many different institutions and fields of space research, the book offers discussions ranging from definitions and historical knowledge to operational issues and methods of analysis. Given that extremes in ionizing radiation, ionospheric irregularities, and geomagnetically induced currents may have the potential to disrupt our technologies or pose danger to human health, it is increasingly important to synthesize the information available on not only those consequences but also the origins and predictability of such events. Extreme Events in Geospace: Origins, Predictability, and Consequences is a valuable source for providing the latest research for geophysicists and space weather scientists, as well as industries impacted by space weather events, including GNSS satellites and radio communication, power grids, aviation, and human spaceflight. The list of first/second authors includes M. Hapgood, N. Gopalswamy, K.D. Leka, G. Barnes, Yu. Yermolaev, P. Riley, S. Sharma, G. Lakhina, B. Tsurutani, C. Ngwira, A. Pulkkinen, J. Love, P. Bedrosian, N. Buzulukova, M. Sitnov, W. Denig, M. Panasyuk, R. Hajra, D. Ferguson, S. Lai, L. Narici, K. Tobiska, G. Gapirov, A. Mannucci, T. Fuller-Rowell, X. Yue, G. Crowley, R. Redmon, V. Airapetian, D. Boteler, M. MacAlester, S. Worman, D. Neudegg, and M. Ishii. Helps to define extremes in space weather and describes existing methods of analysis Discusses current scientific understanding of these events and outlines future challenges Considers the ways in which space weather may affect daily life Demonstrates deep connections between astrophysics, heliophysics, and space weather applications, including a discussion of extreme space weather events from the past Examines national and space policy issues concerning space weather in Australia, Canada, Japan, the United Kingdom, and the United States
Download or read book Introduction to Satellite Remote Sensing written by William Emery and published by Elsevier. This book was released on 2017-08-30 with total page 872 pages. Available in PDF, EPUB and Kindle. Book excerpt: Introduction to Satellite Remote Sensing: Atmosphere, Ocean and Land Applications is the first reference book to cover ocean applications, atmospheric applications, and land applications of remote sensing. Applications of remote sensing data are finding increasing application in fields as diverse as wildlife ecology and coastal recreation management. The technology engages electromagnetic sensors to measure and monitor changes in the earth’s surface and atmosphere. The book opens with an introduction to the history of remote sensing, starting from when the phrase was first coined. It goes on to discuss the basic concepts of the various systems, including atmospheric and ocean, then closes with a detailed section on land applications. Due to the cross disciplinary nature of the authors’ experience and the content covered, this is a must have reference book for all practitioners and students requiring an introduction to the field of remote sensing. Provides study questions at the end of each chapter to aid learning Covers all satellite remote sensing technologies, allowing readers to use the text as instructional material Includes the most recent technologies and their applications, allowing the reader to stay up-to-date Delves into laser sensing (LIDAR) and commercial satellites (DigitalGlobe) Presents examples of specific satellite missions, including those in which new technology has been introduced
