Results 11 to 20 of about 101 (79)

INVERSION OF BACKSCATTER IONOGRAMS INTO QUASI-PARABOLIC IONOSPHERIC LAYER PARAMETERS

Solar-Terrestrial Physics, 2020
We present an inversion scheme of the backscatter signal leading edge into parameters of the quasi-parabolic electron density profile, which is based on the comparison of experimental and calculated minimum delays of scattered signals with corresponding ...
S.N. Ponomarchuk, M.S. Penzin
doaj   +1 more source

HF radar observations of high-aspect angle backscatter from the E-region [PDF]

Annales Geophysicae, 2004
We present evidence for the observation of high-aspect angle HF radar backscatter from the auroral electrojets, and describe the spectral characteristics of these echoes. Such backscatter is observed at very near ranges where ionospheric refraction is
S. E. Milan, M. Lester, T. K. Yeoman, T. R. Robinson, M. V. Uspensky, J.-P. Villain   +5 more
doaj   +1 more source

Southern high-latitude Digisonde observations of ionosphere E-region Bragg scatter during intense lacuna conditions [PDF]

Annales Geophysicae, 2004
During summer months at solar cycle minimum, F-region lacuna and slant-Es conditions (SEC) are common features of daytime ionograms recorded around local magnetic noon at Casey, Antarctica. Digisonde measurements of drift velocity height profiles show
D. P. Monselesan, D. P. Monselesan, R. J. Morris, P. L. Dyson, M. R. Hyde, M. R. Hyde   +5 more
doaj   +1 more source

Radar observations of field-aligned plasma irregularities in the SEEK-2 campaign [PDF]

Annales Geophysicae, 2005
During the Sporadic E Experiment over Kyushu 2 (SEEK-2) campaign, field-aligned irregularities (FAIs) associated with midlatitude sporadic-E (Es) layers were observed with two backscatter radars, the Lower Thermosphere Profiler Radar (LTPR) and the ...
S. Saito, M. Yamamoto, S. Fukao, M. Marumoto, R. T. Tsunoda   +4 more
doaj   +1 more source

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

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

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

Optimizing HAARP Beam Pattern for Generation of Strong F‐Region Field‐Aligned Irregularities

Radio Science, Volume 61, Issue 7, July 2026.
Abstract Field‐aligned irregularities (FAIs) are the signatures of plasma turbulence and convection in the mid‐ and high‐latitude F‐region ionosphere, and also provide coherent backscatter targets for HF radars. To serve irregularity generation and characterization studies, we conducted experiments at the High‐frequency Active Auroral Research Program (
T. S. Anderson, E. H. Lay, I. T. Cummings, C. A. Jeffery, P. A. Bernhardt, M. McCarrick, W. A. Bristow, S. J. Briczinski   +7 more
wiley   +1 more source

The Turbulence Properties of 150‐km Echoes in the Lower Ionosphere

Geophysical Research Letters, Volume 53, Issue 12, 28 June 2026.
Abstract The valley region ionosphere spans from approximately 120–200 km in altitude, and hosts a wide range of plasma, neutral, and solar interactions that create and maintain the ionosphere. In this region a ubiquitous and mysterious source of radar echoes called “150‐km echoes” has been observed since the 1960s.
William J. Longley, Lindsay V. Goodwin, Chirag R. Skolar, Nicholas M. Pedatella   +3 more
wiley   +1 more source

To Which Extent the Surface Water Ocean Topography (SWOT) Mission Is Currently Able to Monitor Water Surface Elevation and Extent on the French Lakes?

Earth and Space Science, Volume 13, Issue 6, June 2026.
Abstract This study (July 2023–December 2025) assesses the SWOT satellite's ability to measure water surface elevation (WSE) and surface water extent (SWE) over diverse French lakes. WSE estimates from SWOT were compared to in situ gauge data and conventional radar altimetry, while SWE was evaluated using the Global Water Watch (GWW) database.
C. Normandin, F. Frappart, C. Moisy, N. Baghdadi, B. Ygorra, L. Bourrel, P. Maisongrande, D. Leroux, J.‐F. Crétaux, J.‐P. Wigneron   +9 more
wiley   +1 more source