Download or read book A Study of Ionospheric F2 Layer Frequency and Gps Total Electron Content written by Muhammad Ayyaz Ameen and published by LAP Lambert Academic Publishing. This book was released on 2012-07 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents the study of relationship between the Total Electron Content (TEC) derived from a Global Positioning System (GPS) receiver and the critical frequency of the F2-layer of the ionosphere in the Equatorial Ionization Anomaly (EIA) region. A practical problem of devising a method to use GPS TEC as a proxy of foF2 was considered for Vanimo, (Papua New Guinea). The study was carried out successfully for southern and northern hemisphere EIA stations. The International Reference Ionosphere (IRI) and electron density profiler NeQuick models were used and the observations were compared with the model outputs. A successive iteration process was applied using the NeQuick model which restricted the TEC to 5% of the GPS TEC value but this could only yield 56% of the foF2 values within a tolerance of 1MHz. A slab thickness model was also used to get the desired output which resulted in 25% success only. The main features of the equatorial anomaly were obtained and verified from both the observed and model datasets. Another dataset from MIT was also used to compare high and low solar activity conditions"
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 Investigation of the Ionospheric Short term Variability written by Zwi Houminer and published by . This book was released on 1998 with total page 19 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reliable HF communications require propagation assessment. Such assessment could be facilitated with the monitoring of ionospheric characteristics by continuously available passive means, i.e, measurements of the total electron content(TEC) using satellite-emitted signals without a need for burdening the electromagnetic spectrum. With the Global Positioning System (GPS) providing instantaneous time delay, or equivalently, TEC, values when needed, an assessment of HF propagation may be available on a near realtime basis. To assess this possibility a one year study of the correlation between TEC and foF2 using GPS time delay observation taken at Matera, Italy was undertaken during 1995-1996. This is a period of minimum solar activity with sunspot numbers varying between 6-18. The observed correlation coefficient varied between 0.55 in the winter of 1996 to about 0.75-0.8 during the summer of 1995. In addition to the seasonal variability of the correlation coefficient, a diurnal variability is also present with the coefficient normally maximizing during the day and minimizing in the predawn periods. The predawn minimum may be due to the contribution of plasmaspheric electron content. The correlation coefficient appears to increase with magnetic activity, indicating that TEC and foF2 behave similarly during magnetically active periods. Distribution of errors between measured foF2 values and predicted ones using a) standard predictions algorithms and b) TEC measurements converted to foF2 from a model of slab thickness, show that the errors are reduced when using TEC observations. The errors would be further reduced if the satellite subionospheric point would approach the location of the foF2 actual measurements.
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 Prediction and Forecasting written by Bruno Zolesi and published by Springer Science & Business Media. This book was released on 2013-09-25 with total page 244 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes how to predict and forecast the state of planet Earth’s ionosphere under quiet and disturbed conditions in terms of dynamical processes in the weakly ionized plasma media of the upper atmosphere and their relation to available modern measurements and modelling techniques. It explains the close relationship between the state of the media and the radio wave propagation conditions via this media. The prediction and forecasting algorithms, methods and models are oriented towards providing a practical approach to ionospherically dependent systems design and engineering. Proper understanding of the ionosphere is of fundamental practical importance because it is an essential part of telecommunication and navigation systems that use the ionosphere to function or would function much better in its nonappearance on the Earth and on any planet with an atmosphere.
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 The Solar Terrestrial Environment written by John Keith Hargreaves and published by Cambridge University Press. This book was released on 1992 with total page 440 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book describes physical conditions in the upper atmosphere and magnetosphere of the Earth.
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 Mapping and Predicting the Earth s Ionosphere Using the Global Positioning System written by Stefan Schaer and published by . This book was released on 1999-01-01 with total page 205 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Algorithm for Accurate Ionospheric Total Electron Content and Receiver Bias Estimation Using GPS Measurements written by Harrison W Bourne and published by . This book was released on 2016 with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt: Abstract : The ionospheric total electron content (TEC) is the integrated electron density across a unit area. TEC is an important property of the ionosphere. Accurate estimation of TEC and TEC spatial distributions are needed for many space-based applications such as precise positioning, navigation, and timing. The Global Positioning System (GPS) provides one of the most versatile methods for measuring the ionosphere TEC, as it has global coverage, high temporal resolution, and relatively high spatial resolution. The objective of this thesis is to develop an algorithm for accurate estimation of the TEC using dual-frequency GPS receiver measurements and simultaneously estimate the receiver hardware bias in order to mitigate its effect on the TEC. This method assumes the TEC in the portion of sky visible to the receiver can be represented as a two dimensional sheet with an absolute value and spacial gradients with respect to latitude and longitude. A code-phase multipath noise estimation algorithm is integrated with the TEC estimation process to mitigate environmental multipath contamination of the measurements. The integrated algorithm produces an approximate map of local TEC using a single dual-frequency receiver while minimizing both multipath induced errors and the receiver hardware bias. The goal of this method is to provide an accurate map of the ionosphere TEC, in the region local to the receiver, without the need for a network of receivers and in the absence of knowledge of the receiver hardware induced bias. This thesis describes the algorithm, its implementation, and attempts to validate the method through comparison with incoherent scatter radar (ISR) data from low, mid, and high latitude locations.
Download or read book Satellite Positioning written by Shuanggen Jin and published by BoD – Books on Demand. This book was released on 2015-03-11 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt: Satellite positioning techniques, particularly global navigation satellite systems (GNSS), are capable of measuring small changes of the Earths shape and atmosphere, as well as surface characteristics with an unprecedented accuracy. This book is devoted to presenting recent results and development in satellite positioning technique and applications, including GNSS positioning methods, models, atmospheric sounding, and reflectometry as well their applications in the atmosphere, land, oceans and cryosphere. This book provides a good reference for satellite positioning techniques, engineers, scientists as well as user community.
Download or read book International Reference Ionosphere Workshop 1999 written by Karl Rawer and published by . This book was released on 2001 with total page 198 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Prediction of Total Electron Content Using the International Reference Ionosphere written by L. F. McNamara and published by . This book was released on 1983 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: The International Reference Ionosphere (IRI) is a model of the ionosphere, based on experimental data, that has been proposed as a standard ionospheric model. As such, it should be tested extensively to determine its range of validity. One of the ways in which the electron density profile given by the IRI, especially above the peak of the F layer, can be tested is to compare calculated and observed values of total electron content (TEC). We have therefore studied the discrepancies between calculated and observed values of TEC recorded at 15 stations covering a wide range of longitudes and latitudes mainly in the northern hemisphere, and mainly for high levels of solar activity. We have found that the IRI produces reasonably accurate values of TEC at mid- and high-latitudes, but that if greatly underestimates the daytime values of TEC at low latitudes. We conclude therefore that the daytime electron density profile given by the IRI is reasonably accurate at mid- and high-latitudes; at least above the peak of the F2 layer. The situation at low latitudes clearly requires more work, and we have suggested two possible lines of study. The generally low discrepancies at night indicate that the nighttime electron density profiles given by the IRI correspond fairly closely to the actual profiles.
Download or read book GNSS Atmospheric Seismology written by Shuanggen Jin and published by Springer. This book was released on 2019-05-30 with total page 315 pages. Available in PDF, EPUB and Kindle. Book excerpt: GNSS can detect the seismic atmospheric-ionospheric variations, which can be used to investigate the seismo-atmospheric disturbance characteristics and provide insights on the earthquake. This book presents the theory, methods, results, and modeling of GNSS atmospheric seismology. Sesimo-tropospheric anomalies, Pre-/Co-/Post-seismic ionospheric disturbances, epicenter estimation, tsunami and volcano ionospheric disturbances, and volcanic plumes detection with GNSS will be presented and discussed per chapter in the book.
Download or read book Ionospheric Total Electron Content Estimation for Single frequency Global Positioning System Receivers written by Carey A. Smith and published by . This book was released on 1987 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Study of the Frequency Spectrum of Fluctuations in the Total Electron Content of the Ionosphere written by Malcolm Richard Kennedy and published by . This book was released on 1969 with total page 188 pages. Available in PDF, EPUB and Kindle. Book excerpt:
