Results 141 to 150 of about 1,219 (180)
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New input to IRI from the worldwide digisonde network
Advances in Space Research, 1994Abstract Electron density profiles derived from Digisonde ionograms at Argentia, Millstone Hill, Wallops Island, Bermuda, Dourbes and Karachi are compared with IRI model prediction. Four months of data for 1989/90 were analyzed. For a number of station/months N(h) profiles were available every 15 or 30 minutes providing a good statistical database ...
B.W. Reinisch, C.F. Chen
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Exploring Digisonde Ionogram Data with SAO-X and DIDBase
AIP Conference Proceedings, 2008A comprehensive suite of software tools for ionogram data analysis and archiving has been developed at UMLCAR to support the exploration of raw and processed data from the worldwide network of digisondes in a low-latency, user-friendly environment.
Grigori M. Khmyrov +9 more
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Comparison of CHAMP and Digisonde plasma frequencies at Jicamarca, Peru
Radio Science, 2007Ionospheric plasma frequencies at the altitude of the CHAMP satellite have been deduced from ionosonde true‐height profiles for Jicamarca, Peru, and have been compared with the in situ measurements made by CHAMP. The differences between the plasma frequencies have been found to be well within the uncertainties associated with the ionosonde profiles ...
L. F. McNamara +3 more
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High latitude Digisonde measurements and their relevance to IRI
Advances in Space Research, 1995Abstract Digisondes operating at high latitudes provide new insights into the structure and dynamics of the polar cap and auroral ionosphere. These instruments derive the electron density profiles from vertical incidence ionograms, and the horizontal and vertical plasma velocities using the interferometric Doppler imaging drift technique.
B.W. Reinisch +3 more
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Digisonde observations of TIDs with frequency and angular sounding technique
Advances in Space Research, 2012A technique for studying ionospheric wavelike phenomena, primarily AGW/TID events, is developed based on the solution of the problem of radio wave propagation in ionospheric plasma disturbed by wavelike processes. A perfectly reflecting surface model is used for representing TIDs propagating at ionospheric heights. This technique is a generalization of
V.V. Paznukhov +2 more
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Plasmaspheric electron content derived from GPS TEC and digisonde ionograms
Advances in Space Research, 2004Abstract The plasmaspheric electron content is extracted from the residuals of GPS-derived TEC measurements from estimates of the electron content obtained by a ground-based ionosonde at Athens (38°N, 23.5°E) over a 12-month time period. The plasmaspheric electron content exhibits a diurnal variation with a morning minimum and an evening maximum ...
Belehaki, A. +2 more
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Automatic Scaling of Digisonde Ionograms Test and Evaluation Report.
1982Abstract : Ionograms contain as basic information the virtual range versus frequency. The Digisonde 128PS also measures amplitude, phase, polarization, incidence angle and the spectral signature of the echoes. This allows automatic scaling of the ionograms and conversion to vertical electron density profiles. This report discusses the automatic scaling
Robert R. Gamache +2 more
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Sporadic E tidal variabilities and characteristics observed with the Cyprus Digisonde
Journal of Atmospheric and Solar-Terrestrial Physics, 2014Abstract In this study, ionogram observations made with the Cyprus digisonde (35°N; 33°E) are analyzed by applying an ionosonde height–time–intensity (HTI) methodology. The aim is to study dominant periodicities and diurnal patterns in occurrence and altitude transport of sporadic E (Es) and intermediate descending layers (IDL), which are impacted ...
Christina Oikonomou +3 more
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Digisonde 256 RF Power Tests at Wallops Island.
1986Abstract : A Digisonde 256 ionosonde system was operated at Wallops Island, VA for a period of two weeks at transmitter power levels ranging from 30 watts to 7 k Watts. This data and the analysis contained in the report should determine for mid-latitude users, the minimum power required to make acceptable measurements.
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Comparison between IRI predictions and digisonde measurements at low latitude station
Advances in Space Research, 1996Abstract The Digisonde database from Cachoeira Paulista (22.5° S, 45° W) is used to compare the observations with the IRI predictions. The data were registered during some periods from 1990 to 1993. The comparison is made for the F region parameters NmF2 and hmF2 and for true height profiles as well.
I.S. Batista +3 more
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