Results 11 to 20 of about 3,051 (167)

An analytical model for Doppler frequency variations of ionospheric HF sounding caused by SSC [PDF]

Journal of Geophysical Research: Space Physics, 2010
A theoretical model to interpret the deviations of the Doppler sounding radio frequency during the SSC is proposed. The Doppler response is composed from long‐period deviation with time scale ∼10 min and short‐lived (∼1 min) positive spike. For the interpretation of this spike, the variations of Doppler velocity induced by compressional and Alfvén ...
V. Pilipenko, E. Fedorov, K. Yumoto, A. Ikeda, T. R. Sun   +4 more
openaire   +3 more sources

Exploring HF‐induced ionospheric turbulence by Doppler sounding and stimulated electromagnetic emissions at the High Frequency Active Auroral Research Program heating facility [PDF]

Radio Science, 2016
AbstractWe report on the features of the F region plasma perturbations during HF heating experiments at the High Frequency Active Auroral Research Program facility in March–April 2011 and May–June 2014. The diagnostics included multifrequency Doppler (phase) sounding (MDS) and stimulated electromagnetic emission (SEE).
Evgeny N. Sergeev, Alexey V. Shindin, Savely M. Grach, Gennady M. Milikh, Evgeny V. Mishin, Paul A. Bernhardt, Carl L. Siefring, Stanley J. Briczinski, Michael J. McCarrick   +8 more
openaire   +3 more sources

Long-distance HF radio waves propagation during the April 2023 geomagnetic storm by measurements in Antarctica, in Europe, and aboard RV Noosfera

Український антарктичний журнал, 2023
The paper aims at an experimental study of the mechanisms of long-distance high-frequency (HF) propagation and spatial and temporal variations of the ionospheric parameters during the first hours of a severe geomagnetic storm of April 23, 2023 by ...
A. Zalizovski, Y. Yampolski, I. Stanislawska, O. Koloskov, O. Budanov, O. Bogomaz, B. Gavrylyuk, A. Sopin, A. Reznychenko, A. Kashcheyev, S. Kashcheyev, V. Lisachenko   +11 more
doaj   +1 more source

The shock-acoustic waves generated by earthquakes [PDF]

, 2000
We investigate the form and dynamics of shock-acoustic waves generated by earthquakes. We use the method for detecting and locating the sources of ionospheric impulsive disturbances, based on using data from a global network of receivers of the GPS ...
Afraimovich, E. L., Perevalova, N. P., Plotnikov, A. V., Uralov, A. M.   +3 more
core   +12 more sources

HF-Induced Modifications of the Electron Density Profile in the Earth’s Ionosphere Using the Pump Frequencies near the Fourth Electron Gyroharmonic

Remote Sensing, 2021
We discuss results on plasma density profile modifications in the F-region ionosphere that are caused by HF heating with the frequency f0 in the range [(−150 kHz)–(+75 kHz)] around the fourth electron gyroharmonic 4fc.
Alexey V. Shindin, Evgeny N. Sergeev, Savely M. Grach, Gennady M. Milikh, Paul Bernhardt, Carl Siefring, Michael J. McCarrick, Yulia K. Legostaeva   +7 more
doaj   +1 more source

Letter to the editor
CUTLASS observations of a high-m ULF wave and its consequences for the DOPE HF Doppler sounder [PDF]

Annales Geophysicae, 1999
The CUTLASS (Co-operative UK Twin Located Auroral Sounding System) Finland HF radar, whilst operating in a high spatial and temporal resolution mode, has measured the ionospheric signature of a naturally occurring ULF wave in scatter artificially ...
D. M. Wright, D. M. Wright, T. K. Yeoman
doaj   +1 more source

Observations of Pc 3-4 and Pi 2 geomagnetic pulsations in the low-latitude ionosphere [PDF]

Annales Geophysicae, 1999
Day-time Pc 3–4 (~5–60 mHz) and night-time Pi 2 (~5–20 mHz) ULF waves propagating down through the ionosphere can cause oscillations in the Doppler shift of HF radio transmissions that are correlated with the magnetic pulsations recorded on the ground.
R. A. Marshall, R. A. Marshall, R. A. Marshall, F. W. Menk, F. W. Menk   +4 more
doaj   +1 more source

A Software-Defined Channel Sounder for Industrial Environments with Fast Time Variance [PDF]

, 2018
Novel industrial wireless applications require wideband, real-time channel characterization due to complex multipath propagation. Rapid machine motion leads to fast time variance of the channel's reflective behavior, which must be captured for radio ...
Block, Dimitri, Fliedner, Niels Hendrik, Meier, Uwe   +2 more
core   +3 more sources

STATISTIC OF SEASONAL AND DIURNAL VARIATIONS OF DOPPLER FREQUENCY SHIFT OF HF SIGNALS AT MID-LATITUDE RADIO PATH [PDF]

Radio Physics and Radio Astronomy, 2020
Purpose: An experimental study of signatures of traveling ionospheric disturbances (TID) observed in diurnal-seasonal variations of the parameters of probe HF signals propagating on theoblique single-hop RWM–LFO radio path, derived from the yearlong ...
A. I. Reznychenko, A. V. Koloskov, A. O. Sopin, Y. M. Yampolski   +3 more
doaj   +1 more source

Searching for effects caused by thunderstorms in midlatitude sporadic E layers [PDF]

, 2017
Possible thunderstorm - sporadic E (Es) layer coupling effects are investigated during two measurement periods, one in 2013 and one in 2014. The analysis was based on ionospheric observations obtained from a Digisonde at Pruhonice, the Czech Republic, an
Barta, Veronika, Bencze, Pál, Berényi, Kitti A., Buresova, Dalia, Bór, József, Chum, Jaroslav, Haldoupis, Christos, Kis, Árpád, Popek, Martin, Pozoga, Mariusz, Sátori, Gabriella   +10 more
core   +2 more sources