Ionospheric Scintillation Modeling Needs and Tricks

Ionospheric Scintillation Modeling Needs and Tricks

Author: Shishir Priyadarshi

Publisher:

Published: 2022

Total Pages: 0

ISBN-13:

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The wavelength of the radio-wave satellite signal is of the order of the minimal small-scale ionospheric irregularities (i.e., a few centimeters). As the satellite signal passes through the ionosphere, its interaction with the ionospheric irregularity structures causes refraction, reflection, and polarization in the satellite signal. Ionospheric irregularities degrade the trans-ionospheric radio-wave signal quality, between the satellite and the receivers, due to scintillation. The physics-based model often fails to produce global morphology during the extreme solar events, whereas empirical models based on the ionospheric scintillation data demonstrate better quality to forecast the scintillation effects during extreme solar event. It is really tricky to make a scintillation model that is sensitive to low and high solar activities as well as extreme solar events simultaneously. In the presented book chapter, we will discuss/review the needs and tricks of modeling ionospheric scintillation during extreme solar events as well as all weather and latitudinal cases. There are several aspects that influence the scintillation occurrence, its strength, and global distribution. The latitudinal dependence, local weather, solar/geomagnetic activity conditions, and local times are the widely accepted factors that control and influence ionospheric scintillation most. This book chapter discusses all these aspects and also suggests the ways to cast aside those factors that led to the wrong measure of scintillation indices.


Satellites Missions and Technologies for Geosciences

Satellites Missions and Technologies for Geosciences

Author: Vladislav Demyanov

Publisher: BoD – Books on Demand

Published: 2020-07-22

Total Pages: 184

ISBN-13: 1789859956

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Being a vital modern technology, satellite systems for navigation, telecommunication, and geosciences have developed rapidly in the last 25 years. Modern satellite technologies have become a base of our civilization and support our day-to-day activity in both practice and geosciences. This book is devoted to GNSS-remote sensing for ionosphere research, modeling and mitigation techniques to diminish the ionosphere and multipath impacts on GNSS, and survey of the modern satellite missions and technologies. We hope that the experts’ opinions presented in the book will be interesting for the research community and students in the area of satellites and space missions as well as in engineering and geoscience research.


High Latitude Models, Observations and Analysis of Ionospheric Scintillations

High Latitude Models, Observations and Analysis of Ionospheric Scintillations

Author: Jules Aarons

Publisher:

Published: 1973

Total Pages: 72

ISBN-13:

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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.


Global Morphology of Ionospheric Scintillations II

Global Morphology of Ionospheric Scintillations II

Author: Jules Aarons

Publisher:

Published: 1975

Total Pages: 30

ISBN-13:

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Updating a review of the global morphology of ionospheric scintillations published in 1971, this study adds additional experimental studies on familiar topics to newer types of measurements of ionospheric irregularities, including in situ experiments and artificial heating of the F-layer.


Satellites Missions and Technologies for Geosciences

Satellites Missions and Technologies for Geosciences

Author: Vladislav Demyanov

Publisher:

Published: 2020

Total Pages:

ISBN-13: 9781789853018

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"Being a vital modern technology, satellite systems for navigation, telecommunication, and geosciences have developed rapidly in the last 25 years. Modern satellite technologies have become a base of our civilization and support our day-to-day activity in both practice and geosciences. This book is devoted to GNSS-remote sensing for ionosphere research, modeling and mitigation techniques to diminish the ionosphere and multipath impacts on GNSS, and survey of the modern satellite missions and technologies. We hope that the experts' opinions presented in the book will be interesting for the research community and students in the area of satellites and space missions as well as in engineering and geoscience research" -- IntechOpen.


A Proposed Index for Measuring Ionospheric Scintillation

A Proposed Index for Measuring Ionospheric Scintillation

Author: H. E. Whitney

Publisher:

Published: 1968

Total Pages: 28

ISBN-13:

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Signals from radio star sources and satellites are regularly used for studying ionospheric irregularities. Amplitude and phase deviations can be imposed on the signals from these sources as they traverse the ionosphere. A parameter frequently used to describe the magnitude of this scintillation effect is scintillation index. An experiment was designed to correlate various methods of making scintillation measurements; observations were made at 40 MHz using the ionospheric beacon, S-66. It is shown that when the law of the receiver detector is known, a conversion method allows comparison of data and statistics on scintillation index. A simplified method of scaling scintillation index is described. The accuracy of the simplified method is determined by a comparison with measurements of scintillation index by machine computation.


Model of Equatorial Scintillations from in Situ Measurements

Model of Equatorial Scintillations from in Situ Measurements

Author: Sunanda Basu

Publisher:

Published: 1976

Total Pages: 32

ISBN-13:

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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).


The Dynamical Ionosphere

The Dynamical Ionosphere

Author: Massimo Materassi

Publisher: Elsevier

Published: 2019-11-28

Total Pages: 337

ISBN-13: 0128147830

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The Dynamical Ionosphere: A Systems Approach to Ionospheric Irregularity examines the Earth’s ionosphere as a dynamical system with signatures of complexity. The system is robust in its overall configuration, with smooth space-time patterns of daily, seasonal and Solar Cycle variability, but shows a hierarchy of interactions among its sub-systems, yielding apparent unpredictability, space-time irregularity, and turbulence. This interplay leads to the need for constructing realistic models of the average ionosphere, incorporating the increasing knowledge and predictability of high variability components, and for addressing the difficulty of dealing with the worst cases of ionospheric disturbances, all of which are addressed in this interdisciplinary book. Borrowing tools and techniques from classical and stochastic dynamics, information theory, signal processing, fluid dynamics and turbulence science, The Dynamical Ionosphere presents the state-of-the-art in dealing with irregularity, forecasting ionospheric threats, and theoretical interpretation of various ionospheric configurations. Presents studies addressing Earth’s ionosphere as a complex dynamical system, including irregularities and radio scintillation, ionospheric turbulence, nonlinear time series analysis, space-ionosphere connection, and space-time structures Utilizes interdisciplinary tools and techniques, such as those associated with stochastic dynamics, information theory, signal processing, fluid dynamics and turbulence science Offers new data-driven models for different ionospheric variability phenomena Provides a synoptic view of the state-of-the-art and most updated theoretical interpretation, results and data analysis tools of the "worst case" behavior in ionospheric configurations