scholarly journals Features of amplitude and Doppler frequency variation of ELF/VLF waves generated by “beat-wave” HF heating at high latitudes

2014 ◽  
Vol 41 (13) ◽  
pp. 4442-4448 ◽  
Author(s):  
E. D. Tereshchenko ◽  
O. I. Shumilov ◽  
E. A. Kasatkina ◽  
A. D. Gomonov
Keyword(s):  
Doppler Frequency ◽  
Frequency Variation ◽  
High Latitudes ◽  
Hf Heating ◽  
Vlf Waves

scholarly journals Magnetospheric injection of ELF/VLF waves with modulated or steered HF heating of the lower ionosphere

2011 ◽  
Vol 116 (A6) ◽  
pp. n/a-n/a ◽  
Author(s):  
M. B. Cohen ◽  
U. S. Inan ◽  
D. Piddyachiy ◽  
N. G. Lehtinen ◽  
M. Gołkowski
Keyword(s):  
Lower Ionosphere ◽  
Hf Heating ◽  
Vlf Waves

The polarization characteristics of ELF/VLF waves generated via HF heating experiments of the ionosphere by EISCAT

2018 ◽  
Vol 25 (9) ◽  
pp. 092902 ◽  
Author(s):  
Jutao Yang ◽  
Qingliang Li ◽  
Jianguo Wang ◽  
Shuji Hao ◽  
Guanglin Ma
Keyword(s):  
Polarization Characteristics ◽  
Hf Heating ◽  
Vlf Waves

Motions of neutral hydrogen at high latitudes

1967 ◽  
Vol 31 ◽  
pp. 265-278 ◽  
Author(s):  
A. Blaauw ◽  
I. Fejes ◽  
C. R. Tolbert ◽  
A. N. M. Hulsbosch ◽  
E. Raimond
Keyword(s):  
Surface Density ◽  
Velocity Dispersion ◽  
Neutral Hydrogen ◽  
Hydrogen Gas ◽  
High Latitudes ◽  
Low Velocity

Earlier investigations have shown that there is a preponderance of negative velocities in the hydrogen gas at high latitudes, and that in certain areas very little low-velocity gas occurs. In the region 100° <l< 250°, + 40° <b< + 85°, there appears to be a disturbance, with velocities between - 30 and - 80 km/sec. This ‘streaming’ involves about 3000 (r/100)2solar masses (rin pc). In the same region there is a low surface density at low velocities (|V| < 30 km/sec). About 40% of the gas in the disturbance is in the form of separate concentrations superimposed on a relatively smooth background. The number of these concentrations as a function of velocity remains constant from - 30 to - 60 km/sec but drops rapidly at higher negative velocities. The velocity dispersion in the concentrations varies little about 6·2 km/sec. Concentrations at positive velocities are much less abundant.

Long-term Cyclic Variations of Prominences, Green and Red Coronae over Solar Cycles

2000 ◽  
Vol 179 ◽  
pp. 201-204
Author(s):  
Vojtech Rušin ◽  
Milan Minarovjech ◽  
Milan Rybanský
Keyword(s):  
Emission Lines ◽  
High Latitudes ◽  
Green Line ◽  
Solar Cycles ◽  
The South ◽  
Coronal Emission ◽  
Local Maxima ◽  
The North ◽  
Cyclic Variations

AbstractLong-term cyclic variations in the distribution of prominences and intensities of green (530.3 nm) and red (637.4 nm) coronal emission lines over solar cycles 18–23 are presented. Polar prominence branches will reach the poles at different epochs in cycle 23: the north branch at the beginning in 2002 and the south branch a year later (2003), respectively. The local maxima of intensities in the green line show both poleward- and equatorward-migrating branches. The poleward branches will reach the poles around cycle maxima like prominences, while the equatorward branches show a duration of 18 years and will end in cycle minima (2007). The red corona shows mostly equatorward branches. The possibility that these branches begin to develop at high latitudes in the preceding cycles cannot be excluded.

A FrFT Based Algorithm for Doppler Frequency Rate Estimation from LFM Coherent Pulse Train

2010 ◽  
Vol 32 (11) ◽  
pp. 2718-2723 ◽  
Author(s):  
Hong Li ◽  
Yu-liang Qin ◽  
Yan-peng Li ◽  
Hong-qiang Wang ◽  
Xiang Li
Keyword(s):  
Pulse Train ◽  
Doppler Frequency ◽  
Rate Estimation ◽  
Frequency Rate ◽  
Coherent Pulse
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