Ionospheric Analysis and Ionospheric Modeling


Book Description

Investigations performed towards the development of improved models of the ionosphere are described. The study was directed at improving existing prediction models of ionospheric parameters. This lead to the development of techniques to update on a global basis monthly median predictions of (f sub o) F2 and M(3000)F2. A new electron density model is presented which allows the user to make a full three dimensional ionosphere for use in a variety of HF radio applications. Extensive tests are presented which explore the model's accuracy. Parts of a separate model for the polar region has been consolidated and incorporated in programs for the evaluation of HF performance criteria.







Ionospheric Tomography


Book Description

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.




Ionospheric Prediction and Forecasting


Book Description

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.




Ionospheric Analysis and Ionospheric Modeling


Book Description

This report describes several investigations performed towards improving our ability to communicate through the ionospheric medium. These studies covered two distinct and separate areas. The first was concerned with improvements in ionospheric forecasting in the polar region through the development of empirical models for electron density profiles and ionospheric parameters. The second consisted of the study of various techniques for the establishment of high frequency communication circuit parameters. Attempts have been made to accurately determine ray paths for ionospheres with simple gradients without the use of three dimensional ray tracing techniques. (Author).




Modeling the Bottomside Ionospheric Electron Density Profile


Book Description

A model describing the mid-latitude bottomside electron density profile is presented. The only geophysical input parameters required for the model are critical frequency, M-factor, planetary index (Ap), and 2800 MHz solar radio flux. An empirically-determined formula for calculating H(m)F2 is derived and used in the model. This formula is a function of the M-factor, local time, day number and magnetic activity. The results obtained by comparing predicted profiles to observed electron density profiles are presented in the form of mean percentage errors as a function of height and local time. The New Model IS COMPARED TO A MODEL CURRENTLY IN OPERATIONAL USE AND IS SHOWN TO BE A 10 TO 20 PERCENT IMPROVEMENT. (Author)




Modeling the Ionosphere-Thermosphere


Book Description

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 201. Modeling the Ionosphere-Thermosphere System brings together for the first time a detailed description of the physics of the IT system in conjunction with numerical techniques to solve the complex system of equations that describe the system, as well as issues of current interest. Volume highlights include discussions of: Physics of the ionosphere and thermosphere IT system, and the numerical methods to solve the basic equations of the IT system The physics and numerical methods to determine the global electrodynamics of the IT system The response of the IT system to forcings from below (i.e., the lower atmosphere) and from above (i.e., the magnetosphere) The physics and numerical methods to model ionospheric irregularities Data assimilation techniques, comparison of model results to data, climate variability studies, and applications to space weather Providing a clear description of the physics of this system in several tutorial-like articles, Modeling the Ionosphere-Thermosphere System is of value to the upper atmosphere science community in general. Chapters describing details of the numerical methods used to solve the equations that describe the IT system make the volume useful to both active researchers in the field and students.




Ionospheric Modeling and Propagation Analysis


Book Description

This report describes several studies and the development of computer techniques toward improving the capability of predicting and assessing HF propagation through the ionosphere. These studies included the development of vertical electron density models which can accurately represent observed oblique and vertical ionograms. These models have been represented by a series of functions which describe the individual ionospheric layers and which are analytically integratable to yield expected ray path trajectories. A computer program has been written which incorporates these features and yields results which are two orders of magnitude faster than those available using conventional numerical ray tracing techniques. The technique has been applied to several studies including the simulation of the backscatter leading edge of oblique ionograms and the determination of HF circuit parameters for a specified ground coverage. The results are presented as a function of the change in individual ionospheric layer parameters. (Author).




Ionospheric Modeling


Book Description




Observation, Analysis, and Modeling of Ionospheric Total Electron Content (TEC) and Scintillation Effects


Book Description

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 (