Results 11 to 20 of about 252,065 (75)

Digital radio and its application in the HF (2-30 MHz) band [PDF]

, 2004
The propagation environment at high frequencies (HF, 2-30 MHz) has a significant impact on the performance of radio systems (especially data communications).
Davies, Nigel Clement
core   +6 more sources

Coordinated optical and radar observations of ionospheric pumping for a frequency pass through the second electron gyroharmonic at HAARP [PDF]

, 2007
On 4 February 2005, the High-frequency Active Auroral Research Program (HAARP) facility was operated in O and X mode while pointing into the magnetic zenith to produce artificial optical emissions in the ionospheric F layer. The pump frequency was set to
Senior, Andrew, Pedersen, T., Kosch, Mike J., Bristow, B., Mishin, E., Watkins, B., Hughes, J., Oyama, S.   +7 more
core   +4 more sources

An in-depth analysis on the Quasi-Longitudinal approximations applied to ionospheric ray-tracing, oblique and vertical sounding, and absorption [PDF]

, 2022
For the phase refraction index of high frequency (HF) waves in the ionospheric medium exists a well-established theory. However, under the Quasi-Longitudinal (QL) conditions, scientific literature presents various formulas that are not equivalent and ...
Settimi, Alessandro
core   +1 more source

Mapping ionospheric backscatter measured by the SuperDARN HF radars - part 2: Assessing SuperDARN virtual height models [PDF]

, 2008
The Super Dual Auroral Radar Network (SuperDARN) network of HF coherent backscatter radars form a unique global diagnostic of large-scale ionospheric and magnetospheric dynamics in the northern and southern hemispheres.
T. R. Robinson (7590257), A. Senior, T. J. T. Karhunen (7594313), T. J. T. Karhunen, Chisham, G., Dhillon, R. S., Senior, A., T. K. Yeoman, R. S. Dhillon, L. J. Baddeley (7590143), Dhillion, R. S., D. M. Wright, A. Senior (3255282), R. S. Dhillon (7594310), Karhunen, T. J. T., Yeoman, T. K., Tim K. Yeoman (7583066), G. Chisham, L. J. Baddeley, Robinson, T. R., Wright, D. M., D. M. Wright (7583069), Baddeley, L. J., T. R. Robinson, G. Chisham (7594307)   +24 more
core   +2 more sources

Multi-frequency HF radar measurements of artificial F-region field-aligned irregularities [PDF]

, 2004
International audienceWe present radar backscatter power measurements using the CUTLASS HF radar at Hankasalmi, Finland from F-region field-aligned irregularities induced by HF radio pumping with the EISCAT Heating facility.
A. Senior, Rietveld, Michael T., Kosch, M.J., Borisov, N. D., Honary, F., Rietveld, M. T., Senior, A., T. K. Yeoman, Borisov, N.D., M. T. Rietveld, Kosch, M. J., M. J. Kosch, F. Honary, Yeoman, T. K., N. D. Borisov, Yeoman, T.K.   +15 more
core   +2 more sources

Investigation of the relationship between optical auroral forms and HF radar E region backscatter [PDF]

, 2000
International audienceThe SuperDARN HF radars have been employed in the past to investigate the spectral characteristics of coherent backscatter from L-shell aligned features in the auroral E region.
Milan, S. E., N. Sato, Lester, M., H. Takizawa (7612496), Villain, J.-P., J. -p. Villain, Takizawa, H., M. Lester, N. Sato (7606136), Milan, S.E., S. E. Milan, Stephen E. Milan (7612220), J. P. Villain (7612424), J.-P. Villain, Mark Lester (6477935), Sato, N., H. Takizawa   +16 more
core   +2 more sources

Brief communication "Monitoring ionospheric variations before earthquakes using the vertical and oblique sounding network over China" [PDF]

, 2011
The problem of earthquake prediction has stimulated the research for correlation between seismic activity and ionospheric anomaly. Many observations have shown the existence of anomaly of critical frequency of ionospheric F-region, foF2, before ...
J. Li, J. Wu, Z. Wu, Y. Hu, S. He, Z. Zhao, T. Xu, Y. Liu   +7 more
core   +2 more sources

Interferometric Synthetic Aperture Radar (InSAR) for Monitoring Seasonal Snow

Water Resources Research, Volume 62, Issue 9, September 2026.
Abstract Interferometric Synthetic Aperture Radar (InSAR) offers a potential pathway for measuring seasonal snow water equivalent (SWE) and snow depth at spatial and temporal scales needed for basin‐scale hydrology. First proposed for seasonal snow more than 25 years ago, InSAR uses repeat‐pass radar phase differences to estimate changes in SWE or ...
Jack Tarricone, Ross T. Palomaki, Randall Bonnell, Zachary Hoppinen, Shadi Oveisgharan, Jorge Jorge Ruiz, Hans‐Peter Marshall, Elias J. Deeb, Carrie Vuyovich, Steven A. Margulis, Simon Yueh, Richard R. Forster, Ryan W. Webb, Daniel McGrath, Juha Lemmetyinen, Kelly Elder, Rashmi Shah, Xiaolan Xu   +17 more
wiley   +1 more source

Terrestrial Analogs to Titan for Geophysical Research

Reviews of Geophysics, Volume 64, Issue 2, June 2026.
Abstract Saturn's moon Titan exhibits remarkable parallels to the Earth in many geophysical and geological processes not found elsewhere in the solar system at the present day. These include a nitrogen atmosphere with a condensible gas—methane—replacing the Earth's water, leading to an active meteorology with rainfall and surface manifestations ...
Conor A. Nixon, Samuel Birch, Audrey Chatain, Charles Cockell, Kendra K. Farnsworth, Peter M. Higgins, Stéphane Le Mouélic, Rosaly M. C. Lopes, Michael J. Malaska, Mohit Melwani Daswani, Kelly E. Miller, Catherine D. Neish, Olaf G. Podlaha, Jani Radebaugh, Lauren R. Schurmeier, Ashley Schoenfeld, Krista M. Soderlund, Anezina Solomonidou, Christophe Sotin, Nicholas A. Teanby, Tetsuya Tokano, Steven D. Vance   +21 more
wiley   +1 more source

“Caterpillar” ULF Waves in the Dusk Side Sub‐Auroral Region: Conjugate Observations With SuperDARN, Arase and Ground Magnetometers

Journal of Geophysical Research: Space Physics, Volume 131, Issue 5, May 2026.
Abstract On 23 November 2022, during exceptionally quiet geomagnetic conditions, a distinct ultra‐low frequency (ULF) wave in the Pc5 band (∼2.4 mHz) was observed in the duskside sub‐auroral region by two Canadian SuperDARN (Super Dual Auroral Radar Network) radars.
N. Nishitani, K. Hosokawa, T. Hori, M. Teramoto, P. V. Ponomarenko, A. Shinbori, Y. Obana, A. S. Yukimatu, G. Hussey, Y. Miyoshi, A. Matsuoka, A. Kumamoto, F. Tsuchiya, S. Matsuda, Y. Kasahara, S. Nakamura, I. Shinohara, Y. Zhang, L. Paxton   +18 more
wiley   +1 more source