Results 41 to 50 of about 820,012 (137)

Detection and Classification of Sporadic E Using Convolutional Neural Networks

Space Weather, Volume 22, Issue 1, January 2024.
Abstract In this work, convolutional neural networks (CNN) are developed to detect and characterize sporadic E (Es), demonstrating an improvement over current methods. This includes a binary classification model to determine if Es is present, followed by a regression model to estimate the Es ordinary mode critical frequency (foEs), a proxy for the ...
J. A. Ellis, D. J. Emmons, M. B. Cohen
wiley   +1 more source

Ionospheric electron heating, optical emissions, and striations induced by powerful HF radio waves at high latitudes: Aspect angle dependence [PDF]

, 2003
In recent years, large electron temperature increases of 300% (3000 K above background) caused by powerful HF-radio wave injection have been observed during nighttime using the EISCAT incoherent scatter radar near Tromsø in northern Norway.
Rietveld, M. T., Kosch, Mike J., Leyser, T. B., Blagoveshchenskaya, N. F., Kornienko, V. A., Yeoman, T. K.   +5 more
core   +2 more sources

Comparison of D-region Doppler drift winds measured by the SuperDARN Finland HF radar over an annual cycle using the Kiruna VHF meteor radar [PDF]

, 2003
The SuperDARN chain of oblique HF radars has provided an opportunity to generate a unique climatology of horizontal winds near the mesopause at a number of high latitude locations, via the Doppler shifted echoes from sources of ionisation in the D-region.
N. F. Arnold (7589813), T. R. Robinson (7590257), P. A. Cook, Chapman, Peter J., N. Mitchell, P. A. Cook (7692134), Lester, M., Mitchell, N., Mitchell, Nick, P. J. Chapman, Arnold, Neil E., Robinson, T. R., Chapman, P. J., M. Lester, Cook, Peter A., M. Lester (7589660), P. J. Chapman (7590299), Arnold, N. F., Cook, P. A., T. R. Robinson, Lester, Mark, N. Mitchell (7692137), N. F. Arnold   +22 more
core   +2 more sources

Adaptive Transient And Cw Rf Interference Mitigation In Hf Oth Radar: Experimental Results

, 2008
We introduce an adaptive technique for the joint mitigation of transients and continuous-wave radio-frequency co-channel interference (CW RFI) in high-frequency (HF) over-the-horizon radars (OTHRs). The performance of this technique is illustrated using data from an operational surface-wave radar (SECAR) and from recent experimental trials with sky ...
Turcaj, P., Abramovich, Y., Frazer, G.
openaire   +2 more sources

A case study of HF radar spectral width in the post midnight magnetic local time sector and its relationship to the polar cap boundary [PDF]

, 2002
International audienceThe aim of this paper is to advance the current understanding of the spectral width parameter observed by coherent high frequency (HF) radars. In particular, we address the relationship of a frequently observed gradient, between low
J. A. Davies, Davies, J.A., Eglitis, P., P. Eglitis (7605143), P. Eglitis, Woodfield, E.E., Lester, M., M. Lester, J. A. Davies (4412452), Emma E. Woodfield (7657994), M. Lester (7589660), Davies, J. A., E. E. Woodfield, Woodfield, E. E.   +13 more
core   +1 more source

Persistent enhancement of the HF pump-induced plasma line measured with a UHF diagnostic radar at HAARP [PDF]

, 2006
Plasma lines excited by a powerful, high-frequency (HF) radio wave are studied using data obtained with an ultrahigh frequency (UHF) radar at HAARP (High Frequency Active Auroral Research Program) from 3 to 5 February 2005.
Bernhardt, P. A., Heinselman, C. J., Kosch, Mike J., Djuth, F. T., Watkins, B. J., Oyama, S.   +5 more
core   +3 more sources

High frequency surface wave radar (HFSWR) simulator

, 2007
110 p.High Frequency (HF) - Radar ,also known as Over-The-Horizon (OTH) Radar is able to detect targets that are over the horizon up to a few hundreds kilometers, beyond the range of a conventional radar.
Teo, Mia Koon
core   +1 more source

Simultaneous HF measurements of E- and F-region Doppler velocity at large flow angles [PDF]

, 2004
International audienceData collected by the CUTLASS Finland HF radar are used to illustrate the significant difference between the cosine component of the plasma convection in the F-region and the Doppler velocity of the E-region coherent echoes observed
Koustov, A. V., Makarevitch, R. A., F. Honary, Honary, F., R. A. Makarevitch, A. V. Koustov   +5 more
core   +2 more sources

Meridional motions of the afternoon radar aurora, auroral electrojets, and absorption patches under variable IMF conditions [PDF]

, 2004
International audienceThe meridional motions of the CUTLASS HF and STARE VHF coherent echoes, IMAGE equivalent electrojet currents, and IRIS absorption patches during the postnoon/early-evening event of 14 February 2000 are presented.
Uspensky, M. V., M. V. Uspensky, Koustov, A. V., Makarevitch, R. A., F. Honary, Honary, F., R. A. Makarevitch, A. V. Koustov   +7 more
core   +2 more sources

The web of laughter: frontal and limbic projections of the anterior cingulate cortex revealed by cortico-cortical evoked potential from sites eliciting laughter. [PDF]

Philos Trans R Soc Lond B Biol Sci, 2022
Zauli FM, Del Vecchio M, Russo S, Mariani V, Pelliccia V, d'Orio P, Sartori I, Avanzini P, Caruana F.   +8 more
europepmc   +1 more source