Results 141 to 150 of about 3,502 (180)

Digitizing the conventional ionosonde

Radio Science, 1979
This paper discusses the accuracy limitations of the conventional ionosonde and techniques which may be used to improve it and at the same time reduce analysis effort. Add‐on digital equipment is described which may easily be attached to any ionosonde to improve its performance at a low cost.
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The applicability of advanced ionosondes to the IRI

Advances in Space Research, 2003
Abstract The ionosonde has evolved from the early analog film-recording depictor of the ionosphere, into a precision diagnositic instrument. Contemporary monitoring ionosondes occupy an intermediate niche in this evolution. Some of these present digital ionogram images to interpretation experts who use the conveniences of digital data presentation to
J.W. Wright, T.W. Bullett
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Ionosonde observations of pulsating auroras

Canadian Journal of Physics, 1981
An "Australian" type ionosonde with modifications to record virtual height versus time in addition to regular ionograms was used for 23 nights during the "pulsating aurora campaign". Height variations associated with pulsating auroras were noted on 14 nights.
J. W. MacDougall, J. A. Koehler, J. Hofstee, D. J. McEwen   +3 more
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Digital spacecraft ionosondes

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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Legendre coding for digital ionosondes

Radio Science, 2005
A 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, 2013
The 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, Lamartine Nogueira Frutuoso Guimarães, Paulo Roberto Fagundes, José Demísio Simões da Silva   +3 more
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Combination of ionosonde and riomethr data for absorption measurements

Journal of Atmospheric and Terrestrial Physics, 1976
Abstract 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, 2011
The 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, F. Arikan, I. Stanislawska   +2 more
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Vertical Sounders — the Ionosonde

1991
One 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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Preliminary observations with a directional ionosonde

Planetary and Space Science, 1971
The 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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