Results 11 to 20 of about 4,161,881 (190)

Normal Doppler Frequency Shift in Negative Refractive‐Index Systems [PDF]

open access: yesLaser & Photonics Reviews, 2019
AbstractBesides the well‐known negative refraction, a negative refractive‐index material can exhibit another two hallmark features, which are the inverse Doppler effect and backward Cherenkov radiation. The former is known as the motion‐induced frequency shift that is contrary to the normal Doppler effect, and the latter refers to the Cherenkov ...
Xiao Lin, Baile Zhang
openaire   +4 more sources

The application of laser doppler technique to vibration measurement and position control. [PDF]

open access: yes
The laser Doppler interferometer reported here was developed to investigate the possibilities of remote vibration and motion measurements. The method is noncontacting and operates with unprepared targets, using the diffusely scattered light to measure ...
Pleydell, Mark Edward
core   +9 more sources

Developments in target micro-doppler signatures analysis: radar imaging, ultrasound and through-the-wall radar [PDF]

open access: yes, 2013
Target motions, other than the main bulk translation of the target, induce Doppler modulations around the main Doppler shift that form what is commonly called a target micro-Doppler signature.
Soraghan, J. J.   +5 more
core   +5 more sources

Frequency-division-multiplexing technique for imaging metrology [PDF]

open access: yes, 2014
An algorithm to multiplex multiple image captures simultaneously onto a single image sensor at full frame resolution was developed for imaging metrology. Parseval’s theorem was used to obtain the image intensity from image time-series of around typically
Bledowski, Ian A.
core   +7 more sources

Hearing Characteristics and Doppler Shift Compensation in South Indian CF-FM Bats [PDF]

open access: yes, 1980
1. Echolocation pulses, Doppler shift compensation behaviour under laboratory conditions and frequency response characteristics of hearing were recorded inRhinolophus rouxi, Hipposideros speoris andHipposideros bicolor. 2.
Schuller, Gerd
core   +1 more source

Single camera three component planar velocity measurements, using two frequency Planar Doppler Velocimetry (2v-PDV) (2005) [PDF]

open access: yes, 2005
The work presented here describes a method that allows three component velocity measurements to be made, quickly and non-intrusively, across a plane in a flow defined by a laser light sheet. The method, two frequency planar Doppler Velocimetry (2v-PDV)
Charrett, Thomas O. H.   +5 more
core   +1 more source

Multi-frequency observations of E-region HF radar aurora [PDF]

open access: yesAnnales Geophysicae, 2003
Multi-frequency observations of E-region coherent backscatter from decametre waves reveal that auroral echoes tend to comprise two spectral components superimposed, one at low Doppler shifts, below 250 ms-1, and the other Doppler shifted to near ...
S. E. Milan, M. Lester, N. Sato
doaj   +1 more source

Foraging behavior and Doppler shift compensation in echolocating hipposiderid bats, I-Iipposideros bicolor and I-Iipposideros speoris [PDF]

open access: yes, 1984
1. Two hipposiderid bats,H. bicolor andH. speoris, were observed in their natural foraging areas in Madurai (South India). Both species hunt close together near the foliage of trees and bushes but they differ in fine structure of preferred hunting space:
Schuller, Gerd   +2 more
core   +1 more source

Research on Calculation Method of Doppler Centroid Shift from Airborne Synthetic Aperture Radar for Ocean Feature Retrieval

open access: yesLeida xuebao, 2019
Doppler center shift is an important parameter for Synthetic Aperture Radar(SAR) to retrieve ocean surface wind field and ocean surface current field. We present a calculation method of Doppler centroid shift for airborne side-looking SAR.
ZHAO Xianbin   +4 more
doaj   +1 more source

Micro-Motion Parameter Extraction of Multi-Scattering-Point Target Based on Vortex Electromagnetic Wave Radar

open access: yesRemote Sensing, 2022
In addition to traditional linear Doppler shift, the angular Doppler shift in vortex electromagnetic wave (VEMW) radar systems carrying orbital angular momentum (OAM) can provide more accurate target identification micro-motion parameters, especially the
Lijun Bu   +5 more
doaj   +1 more source

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