Results 241 to 250 of about 118,769 (293)
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Atomic Frequency Standard Relativistic Doppler Shift Experiment
28th Annual Symposium on Frequency Control, 1974An experiment has been performed to measure possible space anisotropy as it would effect the frequency of a cesium atomic beam standard clock in a laboratory on earth due to motion relative to external coordinate frames. The cesium frequency was measured as a function of orientation with respect to an atomic hydrogen maser standard.
H.E. Peters, V.S. Reinhardt
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Localization by Doppler Derivatives and Doppler-Shifted Frequencies
IEEE Transactions on Signal ProcessingzbMATH Open Web Interface contents unavailable due to conflicting licenses.
Xiaochuan Ke, K. C. Ho
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Frequency Detuning Control by Doppler Shift
2011In this work, a control strategy for ship parametric roll resonance is developed by changing the frequency of the parametric excitation. This is achieved by varying the ship’s forward speed. This changes the perceived frequency of the waves, known as the encounter frequency (and thus the frequency of parametric excitation), via Doppler shift.
Christian Holden +2 more
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Comparison of methods for turbulence Doppler frequency shift calculation in Doppler reflectometer
Plasma Science and Technology, 2023Abstract The Doppler reflectometer (DR), a powerful diagnostic for the plasma perpendicular velocity (u ⊥) and turbulence measurement, has been widely used in various fusion devices. Many efforts have been put into extracting the Doppler shift from the DR signal. There are several commonly used methods for Doppler shift
Zhong, Xiaoming +18 more
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Laser Doppler velocimeter with optical frequency shifting
Optics & Laser Technology, 1973Abstract A bi-directional laser Doppler velocimeter utilizing optical frequency shifting has been developed. Optical frequency shifting is achieved by using a rotating radial grating. A high diffraction efficiency permits the system to be used in the fringe mode.
J. Oldengarm +2 more
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Dynamic non-uniform phase shift measurement via Doppler frequency shift in vortex interferometer
Optics Letters, 2023A vortex beam interferometer based on Doppler frequency shift is proposed to retrieve the dynamic non-uniform phase shift from the petal-like fringes produced by the coaxial superposition of high-order conjugated Laguerre–Gaussian modes. Unlike the uniform phase shift measurement in which the petal-like fringes rotate as a whole, the fringes due to the
Jingtao Dong +5 more
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A frequency shift maximum frequency follower Doppler demodulator with amplitude correction
Clinical Physics and Physiological Measurement, 1981A commonly used maximum-frequency follower Doppler demodulator uses a variable-frequency voltage controlled filter that requires two good quality multipliers and can be difficult to set up and stabilise. An alternative presented here has the advantage of cheapness, easy setting-up and amplitude independence over about 25 dB giving the potential for ...
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Doppler spectral optical coherence tomography with optical frequency shift
SPIE Proceedings, 2007We propose a new method of flow velocity estimation by analysis of time dependent beating signal using Spectral Optical Coherence Tomography. The oscillatory beating signal is caused by the Doppler shift of light reflected back from a mobile object measured in the interferometric set-up.
M. Wojtkowski +5 more
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Doppler Shift Frequency to Voltage Conversion Techniques
1975Three methods of converting the Doppler signal to voltage proportional to mean velocity are compared. The traditional zero crosser is simple and reliable, however, erroneous readings are obtained in the presence of noise and broad band Doppler signals.
F. D. McLeod, R. Daigle, C. W. Miller
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Optics Letters, 2015
A photonic approach for both wideband Doppler frequency shift (DFS) measurement and direction ambiguity resolution is proposed and experimentally demonstrated. In the proposed approach, a light wave from a laser diode is split into two paths. In one path, the DFS information is converted into an optical sideband close to the optical carrier by using ...
Lu, Bing +5 more
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A photonic approach for both wideband Doppler frequency shift (DFS) measurement and direction ambiguity resolution is proposed and experimentally demonstrated. In the proposed approach, a light wave from a laser diode is split into two paths. In one path, the DFS information is converted into an optical sideband close to the optical carrier by using ...
Lu, Bing +5 more
openaire +2 more sources