Results 191 to 200 of about 2,902 (228)
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Advances in Space Research, 1981
Abstract In cooperation with RCA, Astro-Electronics Division, a digital spacecraft ionosonde has been developed and its prototype built by ULCAR. On-board use of the Direct Discrete Fourier Transform for signal-to-noise enhancement, suppression of unwanted echoes and the identification of echo properties permit several applications.
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Abstract In cooperation with RCA, Astro-Electronics Division, a digital spacecraft ionosonde has been developed and its prototype built by ULCAR. On-board use of the Direct Discrete Fourier Transform for signal-to-noise enhancement, suppression of unwanted echoes and the identification of echo properties permit several applications.
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Legendre coding for digital ionosondes
Radio Science, 2005A 1019 bit Legendre code was evaluated for use in digital ionosondes. Experimental testing was done using the Canadian Advanced Digital Ionosonde (CADI). Theoretically, the 1019 Legendre code autocorrelation function of this new sequence has very low peak sidelobe level of −32.6 dB, and the system signal‐to‐noise‐ratio (SNR) will be improved by 30 dB ...
J. Huang, J. W. MacDougall
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A computational tool for ionosonde CADI's ionogram analysis
Computers & Geosciences, 2013The purpose of this work is to present a new computational tool for ionogram generated with a Canadian Advanced Digital Ionosonde (CADI). This new tool uses the fuzzy relation paradigm to identify the F trace and from this form extract the parameters foF2, h'F, and hpF2. The tool was very extensively tested with ionosondes that operate at low latitudes
Valdir Gil Pillat +3 more
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Combination of ionosonde and riomethr data for absorption measurements
Journal of Atmospheric and Terrestrial Physics, 1976Abstract A method is described for combining ionosonde and riometer data which overcomes limitations in both techniques for the measurement of normal absorption in the lower ionosphere. The usefulness of these techniques is thereby considerably increased.
Kressman, R.I., Piggott, W.R.
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Virtual ionosonde network in conjugate hemisphere
2011 XXXth URSI General Assembly and Scientific Symposium, 2011The global ionosonde network distribution is uneven concentrated on land with gaps over the oceans. Figure 1 demonstrates percentage latitudinal distribution of the critical frequency foF2 provided by global ionosonde network with data volume dominating in Zone 1 (50 to 60°N) and Zone 2 (35 to 45°N) of the Northern hemisphere.
T. L. Gulyaeva +2 more
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Preliminary observations with a directional ionosonde
Planetary and Space Science, 1971The addition of three spaced aerials and minor instrumentation to a conventional ionosonde permits the measurement of the angle-of-arrival of ionospheric reflections. Such a directional ionosonde (which is essentially a swept-frequency interferometer) is described, together with a derivation of the formulae relating the angles-of-arrival to the ...
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Vertical Sounders — the Ionosonde
1991One of the first measurements of ionospheric layer height was reported by Appleton and Barnett in 1926, who used a continuous wave transmitter and a receiver located from 65 to 130 km distant from the transmitter. The ground wave and the skywave arrived at the receiver with a relative phase difference.
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From ionosonde to rocket sonde
Journal of Geophysical Research: Space Physics, 1994The 75th Anniversary of the AGU marks the discovery of the basic features of solar control of the ionosphere. A quarter of a century later our understanding of ionospheric physics was revolutionized by the early rocket era of upper air research that brought the discoveries of solar X ray and XUV radiation.
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2018 2nd URSI Atlantic Radio Science Meeting (AT-RASC), 2018
Travelling Ionospheric Disturbances (TIDs) are ionospheric signatures of atmospheric gravity waves. They can result from a variety of natural or artificial sources. Their identification and tracking is important because the TIDs affect all services that rely on predictable ionospheric radio wave propagation.
Tobias G.W. Verhulst +7 more
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Travelling Ionospheric Disturbances (TIDs) are ionospheric signatures of atmospheric gravity waves. They can result from a variety of natural or artificial sources. Their identification and tracking is important because the TIDs affect all services that rely on predictable ionospheric radio wave propagation.
Tobias G.W. Verhulst +7 more
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Active mode radiosounding on ionosonde "TOMION"
SPIE Proceedings, 2016The article is a brief description of the software developed for operation ionosonde "TOMION" in an accelerated mode active vertical radiosounding of the ionosphere.
R. K. Khaitov +5 more
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