Results 161 to 170 of about 2,360 (197)

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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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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Traveling disturbances originating in the outer ionosphere

Journal of Geophysical Research, 1959
Some observations that have been obtained with variations of the classical echo-sounding method must be interpreted as resulting from perturbation and/or oscillation phenomena occurring in the outer ionosphere. The vertical velocity component of ‘traveling disturbances’ coming from outside and propagating through the ionosphere is determined as 115±35 ...
K. Bibl, K. Rawer
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Traveling ionospheric disturbances associated with nuclear detonations

Journal of Geophysical Research, 1967
The analysis of ionospheric data taken from 54 ionosonde observatories throughout the world indicates the presence of several traveling ionospheric disturbances originating from the five high-altitude nuclear tests conducted over Johnston Island in 1962.
W. J. Breitling, R. A. Kupferman, G. J. Gassmann   +2 more
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Incoherent scatter observations of traveling ionospheric disturbances

Journal of Geophysical Research, 1964
The incoherent scatter technique is used to study large-scale traveling ionospheric disturbances above Puerto Rico. Below the F-region maximum the measurements of disturbance amplitude, period, and direction of phase progression with time (downward) are consistent with the bottomside results of other workers. Above the maximum, however, the surfaces of
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Evidence of Directional Filtering of Travelling Ionospheric Disturbances

Nature Physical Science, 1972
IT has recently been pointed out1 that the strong thermospheric winds would act as a directional filter. In a windy thermosphere an otherwise penetrating gravity wave may become reflected or asymptotically trapped near the lower thermosphere. Because both reflexion and trapping take place below the ionospheric F2 peak, such waves may not excite ...
K. C. YEH, H. D. WEBB, D. H. COWLING
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Analysis of large-scale traveling ionospheric disturbances

Journal of Geophysical Research, 1964
It is shown that an acoustic-gravity wave interpretation of Chan and Villard's observations of large-scale traveling ionospheric disturbances is consistent with theory. By using the dispersion curves and kinetic energy profiles for atmospheric gravity waves recently computed by Pfeffer and Zarichny, Pfeffer and Gersten, and earlier by Press and ...
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Mid-latitude range spread and travelling ionospheric disturbances

Journal of Atmospheric and Terrestrial Physics, 1988
This paper first discusses some early results (most hitherto unpublished) on off-vertical reflections which result from tilted isoionic contours associated with the passage of travelling ionospheric disturbances (TIDs). Azimuth of arrival and zenith angle information on these returning signals is discussed together with the role of these signals in ...
Bowman G.G., Monro P.E.
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HF Doppler studies of traveling ionospheric disturbances

Journal of Atmospheric and Terrestrial Physics, 1968
Abstract Wavelike ionospheric motions observed with a network of CW Doppler sounders are analyzed and found to fall into four separate classes not previously distinguished. The motions of each type are attributed to various kinds of atmospheric waves that interact with the ionosphere.
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