Results 41 to 50 of about 630 (181)

Cognitive HF radar

The Journal of Engineering, 2019
Radars operating in the high-frequency (HF) band can exploit propagation modes other than line-of-sight and are hence widely employed to provide over-the-horizon surveillance and remote sensing.
Stuart Anderson
doaj   +1 more source

Improved Amplitude-Phase Calibration Method of Nonlinear Array for Wide-Beam High-Frequency Surface Wave Radar

Remote Sensing, 2023
The amplitude and phase errors in array elements lead to uncertainties in the estimation of arrival angles (DOA), which, in turn, affect the accuracy of current measurements for high-frequency surface wave radar (HFSWR). To address this issue, this paper
Wei Fu, Han Liu, Zhihui Chen, Shu Yang, Yuandong Hu, Fangqing Wen   +5 more
doaj   +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

Near‐Surface Ocean Current and Its Response to Wind Forcing

Journal of Geophysical Research: Oceans, Volume 131, Issue 9, September 2026.
Abstract Ocean currents near the air‐sea interface are critical for understanding boundary layer processes and advancing coupled models. The near‐surface currents mediate air–sea fluxes and govern the transport of buoyant materials, yet the uppermost meter of the ocean remains sparsely observed and poorly represented in models.
Junzhe Liu, Christopher J. Zappa, Nathan J. M. Laxague   +2 more
wiley   +1 more source

The Parguera Fault System: Possible Quaternary Reactivation of Bedrock Faults in Southwest Puerto Rico

Tectonics, Volume 45, Issue 9, September 2026.
Abstract We present evidence of a previously unrecognized east‐west‐trending normal fault, named the Parguera Fault, in southwest Puerto Rico. The fault is located at the northwestern edge of seismicity from the southwest Puerto Rico seismic sequence that began in 2019, near the coastal town of La Parguera.
Jessica Thompson Jobe, Richard Briggs, Victor Ortega Diaz, Emerson M. Lynch, K. Stephen Hughes, Thomas Pratt, Anjana Shah, Francisco Hernandez, Chris M. Justiniano Vélez, Alberto López‐Venegas, Elizabeth Vanacore, M. Morow Tan, Harrison Gray   +12 more
wiley   +1 more source

Seismo‐ and Tsunami‐Traveling Ionospheric Disturbances of the 29 July 2025 M8.8 Kamchatka Earthquake Observed by CW‐HF Doppler Sounding Systems and Ionosondes in Taiwan and Japan

Geophysical Research Letters, Volume 53, Issue 16, 28 August 2026.
Abstract Doppler frequency shifts (DFSs) recorded by continuous wave‐high frequency Doppler sounding systems and ionograms observed by five ionosondes in Taiwan and Japan are used to study three‐dimensionally seismo‐ and tsunami‐traveling ionospheric disturbances (STIDs and TTIDs) triggered by the 29 July 2025 Mw8.8 Kamchatka earthquake.
Yao‐Chun Chen, Jann‐Yenq Liu, Tien‐Chi Liu, Katsumi Hattori, Jaroslav Chum, Chieh‐Hung Chen, Wen‐Yen Chang, Bor‐Shouh Huang, Rui Song, Horng‐Yuan Yen   +9 more
wiley   +1 more source

Study on the Detectability of the Sky-Surface Wave Hybrid Radar

Journal of Applied Mathematics, 2014
Working in the HF (high-frequency) band and the transmitter and receiver locating separately, the sky-surface wave hybrid radar both has the capabilities of the OTHR (over-the-horizon radar) and the advantage of the bistatic radar. As the electromagnetic
Hou Chengyu, Ke Guo, Shi Tiange, Wang Yuxin   +3 more
doaj   +1 more source

Knowledge-Based Multitarget Ship Tracking for HF Surface Wave Radar Systems [PDF]

IEEE Transactions on Geoscience and Remote Sensing, 2015
These last decades spawned a great interest toward low-power high-frequency (HF) surface-wave (SW) radars for ocean remote sensing. By virtue of their over-the-horizon coverage capability and continuous-time mode of operation, these sensors are also effective long-range early warning tools in maritime situational awareness applications providing an ...
Gemine Vivone, Paolo Braca, Jochen Horstmann   +2 more
openaire   +4 more sources

Liquid Metals in Radio Frequency Applications: A Review of Physics, Manufacturing, and Emerging Technologies

Advanced Electronic Materials, Volume 12, Issue 16, 24 August 2026.
This paper reviews the physics of liquid metals in RF devices, including the influence of mechanical strain on resonance as well as fabrication methods and strategies for designing tunable and strain‐tolerant inductors, capacitors, and antennas.
Md Saifur Rahman, William J. Scheideler
wiley   +1 more source

Signal Data Stream Parameters Passing Ionospheric Communication Links With Fading Caused by Natural Clutter Phenomena

Radio Science, Volume 61, Issue 8, August 2026.
Abstract This paper explores the impact of natural phenomena on signal data transmission across various ionospheric communication channels. The study focuses on three primary phenomena: meteor trails prevalent in the middle‐ and lower‐latitude ionosphere, bubble and plume structures observed around the equatorial ionosphere, and magnetic‐storm‐induced ...
I. Bronfman, Y. Ben‐Shimol, N. Blaunstein   +2 more
wiley   +1 more source