Results 21 to 30 of about 519,750 (303)
High-latitude HF Doppler observations of ULF waves. 1. Waves with large spatial scale sizes [PDF]
Annales Geophysicae, 1997 A quantitative study of observations of the ionospheric signatures of magnetospheric ultra low frequency (ULF) waves by a high-latitude (geographic: 69.6°N 19.2°E) high-frequency Doppler sounder has been undertaken.
D. M. Wright +2 more
doaj +1 more source
Enhanced EISCAT UHF backscatter during high-energy auroral electron precipitation [PDF]
Annales Geophysicae, 2013 Natural enhancements in the backscattered power of incoherent scatter radars up to 5 orders of magnitudes above the thermal backscatter are sometimes observed at high latitudes.
N. M. Schlatter +4 more
doaj +1 more source
Measurements and analysis of multistatic and multimodal micro-Doppler signatures for automatic target classification [PDF]
, 2014 The purpose of this paper is to present an experimental trial carried out at the Defence Academy of the United Kingdom to measure simultaneous multistatic and multimodal micro-Doppler signatures of various targets, including humans and flying UAVs ...
Marcio Perassoli +5 more
core +1 more source
Large Photospheric Doppler Shift in Solar Active Region 12673. I. Field-aligned Flows
The Astrophysical Journal, 2023 Delta ( δ ) sunspots sometimes host fast photospheric flows along the central magnetic polarity inversion line (PIL). Here we study the strong Doppler shift signature in the central penumbral light bridge of solar active region NOAA 12673.
Jiayi Liu +5 more
doaj +1 more source
Analysis of micro-Doppler signatures
IEE Proceedings - Radar, Sonar and Navigation, 2003 Mechanical vibration or rotation of a target or structures on the target may induce additional frequency modulations on the returned radar signal which generate sidebands about the target's Doppler frequency, called the micro-Doppler effect. Micro-Doppler signatures enable some properties of the target to be determined.
V.C. Chen, F. Li, S.-S. Ho, H. Wechsler
openaire +1 more source
Multistatic human micro-Doppler classification of armed/unarmed personnel [PDF]
, 2015 Classification of different human activities using multistatic micro-Doppler data and features is considered in this paper, focusing on the distinction between unarmed and potentially armed personnel.
Griffiths, Hugh +8 more
core +1 more source
Atmosphere, 2023 The vertical velocity data from a Doppler LiDAR situated at the centre of Hong Kong were examined to look for signature of subsidence within the atmospheric boundary layer against a synoptic background.
Pak-Wai Chan +2 more
doaj +1 more source
Dual Illumination Planar Doppler Velocimetry using a Single Camera [PDF]
, 2003 A Planar Doppler Velocimetry (PDV) illumination system has been designed which is able to generate two beams, separated in frequency by about 600 MHz. This allows a common-path imaging head to be constructed, using a single imaging camera instead of ...
Nobes, David S. +7 more
core +1 more source
Experimental measurements of radar signatures of large wind turbine
The Journal of Engineering, 2019 This study presents preliminary results on the signature of a large offshore wind turbine collected using an active S-band radar. The intensity fluctuations of this clutter signal in the range and Doppler domain are characterised, looking at their ...
Francesco Fioranelli +6 more
doaj +1 more source
Attention‐enhanced Alexnet for improved radar micro‐Doppler signature classification
IET Radar, Sonar & Navigation, 2023 This work introduces an attention mechanism that can be integrated into any standard convolution neural network to improve model sensitivity and prediction accuracy with minimal computational overhead.
Shelly Vishwakarma +5 more
doaj +1 more source