Results 11 to 20 of about 47,507 (304)

Direction finding of auroral VLF hiss in auroral zone

Antarctic Record, 1981
A newly developed direction finding ('DF') for auroral hiss based on the measurement of time differences of wave arrival among three spaced points was carried out around Syowa Station (geomag. lat. -70.4°), Antarctica in 1978-1979. It has been found that
Masanori Nishino, Takeo Hirasawa
doaj   +2 more sources

A Novel Nonlinear LPDA Design for HF Direction Finding

International Journal of Antennas and Propagation, 2019
A novel design of log-periodic dipole array (LPDA) for high-frequency direction finding (DF) is presented. The traditional Carrel method employs fixed values of scale factor and spacing factors in LPDA designs. Here, we propose a design method which uses
Xiaofei Ren, Hu Li, Shuxi Gong
doaj   +2 more sources

On Calibration and Direction Finding with Uniform Circular Arrays [PDF]

International Journal of Antennas and Propagation, 2019
Antenna array calibration methods and narrowband direction finding (DF) techniques will be outlined and compared for a uniform circular array. DF is stated as an inverse problem, which solution requires a parametric model of the array itself.
Stephan Häfner, Martin Käske, Reiner Thomä   +2 more
doaj   +2 more sources

Quality Control for Ocean Current Measurement Using High-Frequency Direction-Finding Radar

Remote Sensing, 2023
High-frequency radars (HFRs) are important for remote sensing of the marine environment due to their ability to provide real-time, wide-coverage, and high-resolution measurements of the ocean surface current, wave height, and wind speed.
Shuqin He, Hao Zhou, Yingwei Tian, Da Huang, Jing Yang, Caijun Wang, Weimin Huang   +6 more
doaj   +2 more sources

A Cupola-Shaped Multimode Multiport Antenna for Aerial Direction Finding [PDF]

IEEE Antennas and Wireless Propagation Letters
A multimode multiport antenna (M$^3$PA), constisting of a single conducting structure, is proposed for use with the airborne collision avoidance system (ACAS).
Gerlach, Marc, Manteuffel, Dirk, Grundmann, Lukas, Schäfer, Wolfgang   +3 more
core   +2 more sources

High sensitivity multi‐channel digital receiver for wideband very weak signal direction‐finding classified by machine learning

IET Radar, Sonar & Navigation
For weak signal detection with direction‐finding (DF), this article presents a new receiver design approach that combines our accumulatively increasing receiver sensitivity (AIRS) signal detection algorithm with the compressive‐sensing (CS)‐based DF ...
Chen Wu, Michael Low
doaj   +2 more sources

Two-Dimensional Real-Time Direction-Finding System for UAV RF Signals Based on Uniform Circular Array and MUSIC-WAA

Drones
To address the growing security risks posed by unauthorized unmanned aerial vehicle (UAV) activities, this paper proposes a real-time two-dimensional direction-finding (DF) system for UAVs based on radio frequency (RF) signals.
Jizan Zhu, Kuangang Fan, Qing He, Jingzhen Ye, Aigen Fan   +4 more
doaj   +2 more sources

Collinearity Problems in Passive Target Localization Using Direction Finding Sensors [PDF]

, 2016
In passive target localization using direction finding (DF), there are particular sensor-target placements that cause large biases in the estimates or the failure of estimates to converge to a unique solution.
Drake, Sam, Fidan, Baris, Anderson, Brian, Kannan, Anushiya, Mao, Guoqiang   +4 more
core   +3 more sources

PASSIVE DIRECTION FINDING USING AMPLITUDE AND PHASE COMPARISON TECHNIQUES

, 2014
Amplitude and phase comparison methods are practical direction finding (DF) techniques for electronic support and electronic intelligence systems. The combination of amplitude and phase comparison methods improves the direction finding accuracy and at ...
Serin, Mahmut, Orduyilmaz, Adnan, Yildirim, Alper, Gurbuz, Ali Cafer   +3 more
core   +2 more sources

Design of a High-Gain Single Circular Patch Radiator With a Cavity-Backed Structure Using Multiple SIW Feeders for Monopulse DF-Applications

IEEE Access, 2022
This paper proposes the design of a gain enhanced single circular patch radiator (SCPR) with a cavity-backed structure using multiple substrate integrated waveguide (SIW) feeders for monopulse systems.
Sangwoon Youn, Tae Heung Lim, Byung-Jun Jang, Hosung Choo   +3 more
doaj   +1 more source