Results 161 to 170 of about 1,807 (203)

Spread-F on ionograms

Journal of Atmospheric and Terrestrial Physics, 1970
Abstract Spread- F echoes are not due to partial reflection from small irregularities. Rather they are due to total reflection from large tilted surfaces of ionization. The geometry of these surfaces is examined using ionograms and airglow observations, together with Australian experiments reported in the literature.
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Serum ionogram in heperpyrexia

The Indian Journal of Pediatrics, 1960
Forty-five consecutive cases of pyrexia with temperatures above 103oF occurring in children ranging from one to twelve years of age were studied clinically and for serum electrolyte changes.
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Lossless compression of ionogram data

Proceedings of 13th International Conference on Digital Signal Processing, 2002
A method for lossless compression of binary data is presented. To remove the redundancies among the data points, a linear predictive scheme is proposed and the coefficients are optimised in the sense of minimum mean square error. An arithmetic coder is then used to code the prediction errors.
null Hua Ye, J.C. Devlin, null Guang Deng   +2 more
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The analysis of night-time ionograms

Journal of Atmospheric and Terrestrial Physics, 1975
Abstract The analysis of ionospheric h′(ƒ) records can give appreciable errors at night, when large amounts of ionisation may be present with plasma frequencies less than the minimum recorded frequency ƒ min . The errors depend on both the total amount of low-density ionisation, and on the ionisation gradient near ƒ min .
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Loop structuring of ionogram traces

Journal of Atmospheric and Terrestrial Physics, 1973
Abstract The phenomenon of small scale loop structuring of F-region ionogram traces is investigated; this loop structuring is shown to be caused by high-frequency ray propagation through irregularities in which dN/dz is less than ambient but greater than zero.
J.D. Mathews, B.S. Tanenbaum
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The Interpretation of Topside Sounder Ionograms

Proceedings of the IEEE, 1969
Most of the phenomena observed on Alouette I and Alouette II ionograms are identified and interpreted. Simple as well as complex ionograms are treated, but emphasis is placed on ionograms exhibiting very low electron density, spread-F and field-aligned propagation.
E.L. Hagg, E.J. Hewens, G.L. Nelms
exaly   +2 more sources

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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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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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 ...
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The stability of ionogram analysis techniques

Journal of Atmospheric and Terrestrial Physics, 1982
Abstract Ionograms commonly contain discontinuities or cusps in the virtual-height trace. These produce spurious oscillations in the calculated real heights, when second or higher order analysis techniques are used. The magnitude of this effect is studied using basic discontinuities and model ionograms.
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