Results 201 to 210 of about 5,624 (239)

Automatic scaling of digital ionograms

Radio Science, 1989
A new system has been devised to automatically scale digital ordinary‐ray ionograms. The system has been developed for use at mid‐latitudes and has been trained on a full set of ionograms that are typical of the region. This paper describes the stages adopted in forming, recognizing, and scaling traces from the various ionospheric layers.
Matthew W. Fox, Craig Blundell
openaire   +1 more source

Signal Identification and Trace Extraction for the Vertical Ionogram

IEEE Geoscience and Remote Sensing Letters, 2012
Vertical ionograms suffer from artifacts and distortion due to other users of the high-frequency channel and the ionosphere. The traces of each layer have variable shapes, so the automatic scaling of the vertical ionograms is rather complicated.
Fanfan Su, Zhengyu Zhao, Shipeng Li, Ming Yao, Gang Chen, Yiyang Zhou   +5 more
semanticscholar   +1 more source

Classification of spread-F ionograms

Journal of Atmospheric and Terrestrial Physics, 1962
Abstract Scaling of original ionograms obtained in the polar regions has lead to a classification scheme for spread-F ionograms. Defined are three types of frequency spreading (spreadish-F, furcated-F and spurred-F) and one type of range spreading. Each type is subdivided into species.
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Ionogram inversion using NeQuick2 model

2014 XXXIth URSI General Assembly and Scientific Symposium (URSI GASS), 2014
NeQuick2 is a well-known ionospheric model for electron density computation, utilizing the Epstein layer formulation originally proposed by G. Di Giovanni and S.M. Radicella. In this study, algorithm of NeQuick2 model has been employed for ionogram inversion using MATLAB.
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Some possible coupling echoes on ionograms

Journal of Atmospheric and Terrestrial Physics, 1973
Abstract The possibility of a mode coupling process in thin E S -layers producing extra traces on ionograms is considered. One such trace on an ionogram recorded at Armidale, Australia is examined in detail and a possible coupling mechanism proposed to explain the observed reflections.
C.I Chessell, I.A Bourne, R.A Smith
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Synthesis of three‐dimensional ionograms

Radio Science, 1973
A previously reported method of exact calculation of ray‐path parameters for a spherically symmetric ionosphere with its center of curvature displaced from the center of the earth is extended to permit the synthesis of three‐dimensional ionograms, i.e., group path, azimuthal angle of arrival, and elevation angle of arrival versus frequency, for a ...
openaire   +1 more source

Synthesis of oblique ionograms from vertical ionograms using quasi-parabolic segment models of the ionosphere

Journal of Atmospheric and Terrestrial Physics, 1992
Abstract This paper describes a method of synthesizing oblique ionograms from vertical ionograms based on representing the ionosphere by multiple quasi-parabolic segments (QPS). The advantage of this approach is that it allows analytical solutions to be obtained for several ray parameters when the Earth's magnetic field is neglected and the ...
J. Chen, J.A. Bennett, P.L. Dyson
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Analysis of Stress Ionograms.

1977
Abstract : Anomalous radar returns seen on ionograms following ionospheric barium releases are analyzed to determine their origin and their interpretation. Two types of echoes are identified; one type originates from the barium cloud and the other type from layers formed by the descent of barium ions into the E-region.
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First bistatic oblique‐incidence ionograms between digital ionosondes

Radio Science, 1983
Identical digital ionosondes (dynasondes) at Brighton Colorado and at White Sands Missile Range, New Mexico, 864 km distant, were synchronized for bistatic sounding in multifrequency and fixed frequency recording patterns. Three propagation modes are observed, identified, and reconciled with standard propagation theory; these include one‐hop ...
Wright, J.W., Kressman, R.I.
openaire   +2 more sources

Computer-aided ionogram reduction: Software structure

Advances in Space Research, 1988
Abstract Special software has been developed in view of an automated ionogram reduction and statistical handling of relevant data. Requirement for such software are formulated and possible ways to satisfy these are shown. Distinguishing different levels, a detailed description of system levels and terminal maintenance is given. Much attention is paid
G.M. Emeljanov, I.U. Zukovsky, N.I. Smirnov   +2 more
openaire   +1 more source