Results 21 to 30 of about 134,109 (102)

Ground-based HF to VHF radar calibration by scattering off a stratospheric balloon [PDF]

Atmospheric Measurement Techniques
The knowledge of radar system properties is crucial for judging radar performance and correctly interpreting received raw and analysed data. The most critical part of that is the radiation pattern, which is often very difficult to measure for atmospheric/
T. Renkwitz, T. Renkwitz, M. Clahsen, R. Latteck   +3 more
doaj   +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   +3 more sources

D region HF radar echoes associated with energetic particle precipitation and pulsating aurora [PDF]

, 2008
Milan et al. (2001) identified a class of narrow, slow-moving HF radar backscatter echoes which originate between altitudes of 80 and 100 km, the ionospheric D- and lower E-regions.
Milan, S.E., S. E. Milan, K. Hosokawa, Yamagishi, H., N. Sato, Lester, M., F. Honary, Hosokawa, K., Honary, F., Sato, N., M. Lester, H. Yamagishi   +11 more
core   +2 more sources

DIRECTION FINDING OF HF SIGNALS SCATTERED BY IONOSPHERIC IRREGULARITIES USING SMALL SIZE ANTENNA

Radio Physics and Radio Astronomy, 2016
Purpose: A modification of the Doppler Interferometry Technique is suggested to enable estimating angles of arrival of comparatively broadband HF signals scattered by random irregularities of the ionospheric plasma with the use of small-size near ...
V. G. Galushko, A. V. Zalizovski, S. B. Kascheev, I. I. Pikulik, O. V. Charkina   +4 more
doaj   +1 more source

On the factors controlling occurrence of F-region coherent echoes [PDF]

, 2002
International audienceSeveral factors are known to control the HF echo occurrence rate, including electron density distribution in the ionosphere (affecting the propagation path of the radar wave), D-region radio wave absorption, and ionospheric ...
T. Ogawa, S. Nozawa, A. V. Koustov, D. Andre (7667897), Milan, S.E., D. W. Danskin, Nozawa, S., T. Ogawa (4008053), S. E. Milan (7594526), N. Nishitani, D. Andre, Milan, S. E., Lester, M., S. Nozawa (7672178), D. W. Danskin (7613489), N. Nishitani (7672181), Danskin, D. W., Ogawa, T., M. Lester, A. V. Koustov (7613492), M. Lester (7589660), Andre, D., S. E. Milan, Koustov, A.V., Koustov, A. V., Nishitani, N., Danskin, D.W.   +26 more
core   +2 more sources

Evidence of low‐latitude daytime large‐scale traveling ionospheric disturbances observed by high‐frequency multistatic backscatter sounding system during a geomagnetically quiet period [PDF]

Journal of Geophysical Research: Space Physics, 2012
Observations from the high‐frequency multistatic backscatter sounding radars on a geomagnetically quiet day (minimum Dst = −14 nT) captured the anti‐equatorward propagation of daytime large‐scale traveling ionospheric disturbance (LSTID) at the low‐latitude regions. The observed LSTID was characterized approximately by a meridional propagation speed of
Chen Zhou, Zhengyu Zhao, Guobin Yang, Gang Chen, Yaogai Hu, Yuannong Zhang   +5 more
openaire   +1 more source

The influence of magnetospheric substorms on SuperDARN radar backscatter [PDF]

, 2008
The SuperDARN ionospheric radar network is a leading tool for investigating the near-Earth space environment. However, reductions in ionospheric backscatter have been reported during magnetospheric substorms.
Wild, James A., Grocott, A.
core   +4 more sources

Superdarn radar HF propagation and absorption response to the substorm expansion phase [PDF]

, 2002
International audienceCoherent scatter HF ionospheric radar systems such as SuperDARN offer a powerful experimental technique for the investigation of the magnetospheric substorm.
J. A. Davies, Milan, S. E., Honary, F., T. K. Yeoman (7601525), J. A. Davies (4412452), J. K. Gauld (7674179), F. Honary (7604621), T. K. Yeoman, Davies, J. A., S. E. Milan, J. K. Gauld, F. Honary, Yeoman, T. K., S. E. Milan (7594526), Gauld, J. K.   +14 more
core   +2 more sources

Observation of Shortwave Fadeout Events Using Chinese Dual Auroral Radar Network (CN‐DARN) During the Severe Solar Storm in May 2024

Space Weather, Volume 24, Issue 10, October 2026.
Abstract Shortwave fadeout (SWF) is a typical dayside high‐frequency radio disturbance caused by solar flare‐induced ionospheric ionization enhancement. Using newly built Chinese Dual Auroral Radar Network (CN‐DARN) observations, we investigate two X‐flare‐driven SWFs during the May 2024 geomagnetic superstorm (SYM‐H = −518 nT), on 10 May (pre‐storm ...
Junjie Tong, Jiaojiao Zhang, Hang Li, Wei Wang, Bianlong Zhao, Wenqian Chen, Xiang Deng, Ailan Lan, Jingye Yan, Chi Wang   +9 more
wiley   +1 more source

The Impacts of Tropospheric Gravity Wave‐Generated MSTIDs on Skywaves at Mid‐latitude North American Sector Observed and Modeled Using SuperDARN HF Radars

Radio Science, Volume 61, Issue 9, September 2026.
Abstract Trans‐ionospheric high frequency (HF: 3–30 MHz) response to atmospheric gravity waves (GWs) is studied in the middle‐latitude ionosphere in relation to thunderstorm activity. SuperDARN HF radar observations are compared against the model simulations to quantify the impact of GW‐generated medium‐scale traveling ionospheric disturbances (MSTID ...
S. Chakraborty, P. A. Inchin, S. Debchoudhury, B. Bergsson, M. Zettergren, J. M. Ruohoniemi   +5 more
wiley   +1 more source