Results 191 to 200 of about 5,624 (239)
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Automatic scaling of polar ionograms
Antarctic Science, 2011AbstractThe 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, 1973Abstract 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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, 2016
Scaling oblique ionogram plays an important role in obtaining ionospheric structure at the midpoint of oblique sounding path. The paper proposed an automatic scaling method to extract the trace and parameters of oblique ionogram based on hybrid genetic ...
Huan Song +5 more
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Scaling oblique ionogram plays an important role in obtaining ionospheric structure at the midpoint of oblique sounding path. The paper proposed an automatic scaling method to extract the trace and parameters of oblique ionogram based on hybrid genetic ...
Huan Song +5 more
semanticscholar +1 more source
Journal of Atmospheric and Terrestrial Physics, 1978
Abstract The simulations of trough ionograms by Lobb and Titheridge (1977) are supplemented by calculating a trace caused by rays having a double oblique reflection in the ionosphere and not retracing their paths. It is also shown how the different parts of the traces are caused by echoes of different types.
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Abstract The simulations of trough ionograms by Lobb and Titheridge (1977) are supplemented by calculating a trace caused by rays having a double oblique reflection in the ionosphere and not retracing their paths. It is also shown how the different parts of the traces are caused by echoes of different types.
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Lossless compression of ionogram data
Proceedings of 13th International Conference on Digital Signal Processing, 2002A 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 +2 more
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2017
This chapter explores how the Alouette satellite’s reorientation of global data flows and mass-production of ionograms altered the natural order at the core of DRTE’s research. The satellite’s unexpected reliability demanded an automated system of data analysis.
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This chapter explores how the Alouette satellite’s reorientation of global data flows and mass-production of ionograms altered the natural order at the core of DRTE’s research. The satellite’s unexpected reliability demanded an automated system of data analysis.
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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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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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Ionograms denoising via curvelet transform
Advances in Space Research, 2013Abstract Ionograms are used to obtain important information of the ionosphere. Unfortunately, ionograms are always contaminated by several kinds of noises. In this paper, curvelet transform denoising algorithm is used to obtain high-quality ionograms.
Ziwei Chen +3 more
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Serum ionogram in heperpyrexia
The Indian Journal of Pediatrics, 1960Forty-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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Neural networks for several ionogram features
Radio Science, 1995Several demonstration neural networks will be described that identify certain characteristics of ionograms. The characteristics identified are ordinary and extraordinary F region critical frequency, F1 cusp frequency, sporadic E type C and type H cusp frequencies, and spread F. Accuracy for the neural networks varies, ranging from 50% to 90%.
J. N. Hill, T. H. Koschmieder
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