Results 171 to 180 of about 2,664 (215)

Frequency estimation of travelling ionospheric disturbances

1996 IEEE International Symposium on Circuits and Systems. Circuits and Systems Connecting the World. ISCAS 96, 2002
The use of adaptive filters in estimating the instantaneous frequency of Doppler shifted signals reflected from the ionosphere is addressed in this paper. With the aid of a software simulator, it has been shown that an adaptive linear predictor is effective in extracting the required Doppler shift.
J.M. O'Keefe, D.A. Campbell, L.W. Cahill
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The dispersion of traveling ionospheric disturbances

Journal of Geophysical Research: Space Physics, 1983
The horizontal dispersion of relatively large daytime TID events seen by the Dartmouth rapid‐run ionosonde network is found to conform, at least qualitatively, to that predicted by previous theoretical treatments of freely propagating gravity waves in the presence of dissipation.
M. G. Morgan, B. L. Tedd
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Traveling ionospheric disturbances near London, Canada

Journal of Atmospheric and Solar-Terrestrial Physics, 2009
Abstract Observations of medium scale traveling ionospheric disturbances (TIDs) from near London, Canada (43°N, 81°W geographic) using spaced transmitter technique at 4 MHz have been done for 1 1 2 years. Most of the best data are for daytime TIDs because of the use of 4 MHz.
J.W. MacDougall, G. Li, P.T. Jayachandran   +2 more
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Travelling Disturbances in the Ionosphere

Nature, 1953
MEASUREMENTS of the horizontal velocity of travelling disturbances in the F2 region of the ionosphere have been made in this department over the past three years, using the method described by Munro1. Constant-frequency pulse transmitters were set up at the base station in the Physics Department of the University of Western Australia, and at two other ...
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GPS radio interferometry of travelling ionospheric disturbances

Journal of Atmospheric and Solar-Terrestrial Physics, 1998
Abstract This paper presents some results investigating the new possibilities of radio interferometry of Travelling Ionospheric Disturbances (TIDs) that are based on exploiting standard measurements of transionospheric radio signal characteristics and coordinate-time measurements using dual-frequency multichannel receivers of the Global Positioning ...
E.L. Afraimovich, K.S. Palamartchouk, N.P. Perevalova   +2 more
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On the Relationship Between Traveling Atmospheric Disturbances and Traveling Ionospheric Disturbances

Journal of Geophysical Research: Space Physics
AbstractAs the typical thermospheric/ionospheric wave, traveling atmospheric disturbances (TADs)/traveling ionospheric disturbances (TIDs) always carry and transfer a large amount of energy and momentum during geomagnetic storms. In this study, we conducted a model simulation to explore the relationship between TADs and TIDs.
Bowei Liu, Jing Liu, Xuanqing Liu, Shuhan Li, Libo Liu   +4 more
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Travelling disturbances in the ionosphere

Proceedings of the Royal Society of London. Series A. Mathematical and Physical Sciences, 1950
Methods have been developed for the examination of the horizontal and vertical movements of short-period disturbances in the ionosphere. It has been found that quasi-periodic travelling disturbances with periods of from 10 to 60 min. are of frequent occurrence in the F region by day.
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Travelling disturbances associated with ionospheric storms

Journal of Atmospheric and Terrestrial Physics, 1965
Following each of three geomagnetic sudden commencements, ionospheric disturbances (ionospheric storms) are found to propagate from two isolated locations in high-latitude regions of the Earth. These two positions are conjugate points (magnetically), and are in different locations for each magnetic storm.
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Three-dimensional observations of traveling ionospheric disturbances

Journal of Atmospheric and Terrestrial Physics, 1971
Abstract Twenty-five measurements of vertical and horizontal trace velocities of medium size traveling ionospheric disturbances were made near sunset at Boulder, Colorado from June 1967 through June 1968. The total speeds of the TID's were slightly larger in summer than in winter with a mean value of 143 m/s.
Kenneth Davies, John E. Jones
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Traveling Ionospheric Disturbance Mitigation for OTH Radar

2007 IEEE Radar Conference, 2007
Deflection of HF propagation paths by traveling ionospheric disturbances (TIDs) remains a troubling cause of coordinate registration errors for over-the-horizon (OTH) radar. Bandwidth and coverage limitations in ionospheric soundings preclude the ability to model TID structure in real time in most cases.
L. J. Nickisch, Mark A. Hausman, Sergey Fridman   +2 more
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