Results 171 to 180 of about 1,552 (215)

Backscatter ionogram inversion

2003 Proceedings of the International Conference on Radar (IEEE Cat. No.03EX695), 2004
A backscatter ionogram, BSI, is a plot showing the group path or time delay against operating frequency when using ground-based swept frequency radar. In the case of ground backscatter, the received signals are reflected from distant locations on the Earth's surface.
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On the simulation of backscatter ionograms

Journal of Atmospheric and Solar-Terrestrial Physics, 1997
Abstract An algorithm for the simulation of backscatter ionograms is developed. Propagation is evaluated by numerically ray tracing through an ionosphere consisting of Chapman layers (major layer parameters derived from CCIR and URSI maps). Simulations are performed for a variety of model ionospheres (including some with strongly varying horizontal ...
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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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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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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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Automatic scaling of polar ionograms

Antarctic Science, 2011
AbstractThe Istituto Nazionale di Geosifica e Vulcanologia (INGV) software for automatic scaling of ionograms (Autoscala) was improved by introducing a system to identify D region absorption events, spread-F condition (frequency spreading in the F region), and Z-ray propagation.
Carlo Scotto, Michael Pezzopane
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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 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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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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