Results 181 to 190 of about 1,922,963 (250)
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IRE Transactions on Military Electronics, 1961
Doppler radars are employed for the detection of moving targets whose radar echo area is much smaller than the ground clutter return. Moving targets are separated from clutter on a frequency basis by utilizing the Doppler phenomenon. Continuous-wave Doppler radars have a practical maximum-range capability because the leak-through between the ...
L. P. Goetz, J. D. Albright
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Doppler radars are employed for the detection of moving targets whose radar echo area is much smaller than the ground clutter return. Moving targets are separated from clutter on a frequency basis by utilizing the Doppler phenomenon. Continuous-wave Doppler radars have a practical maximum-range capability because the leak-through between the ...
L. P. Goetz, J. D. Albright
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Pulsed Doppler frequency and carotid stenosis
Journal of Surgical Research, 1987Two hundred and forty-two internal carotid arteries (ICA) were evaluated by independently interpreted arteriography and pulsed Doppler spectrum analysis using ultrasonic arteriography to evaluate the ability of peak systolic frequency (PSF) to predict the degree of internal carotid stenosis.
W M, Blackshear +6 more
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2010 International Waveform Diversity and Design Conference, 2010
Modern military airborne radars are highly sophisticated, multi-mode systems which are required to detect difficult targets in all aspects and over a large range/velocity detection space. There are particular difficulties associated with the airborne case such as the limited antenna aperture, high platform velocity and severe clutter levels which ...
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Modern military airborne radars are highly sophisticated, multi-mode systems which are required to detect difficult targets in all aspects and over a large range/velocity detection space. There are particular difficulties associated with the airborne case such as the limited antenna aperture, high platform velocity and severe clutter levels which ...
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[Doppler effect in cardiology. Continuous Doppler, pulsed Doppler, Doppler color].
Presse medicale (Paris, France : 1983), 1989Echocardiography has contributed to the exploration of the heart by providing much information, and it has even given rise to new semiological concepts. However, abnormalities of intracardial blood flow, notably shunts and regurgitations, could only be diagnosed indirectly from their effects on cardiac cavities.
Y, Houdas +3 more
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Inline ultrasonic rheometry by pulsed Doppler
Ultrasonics, 2006This will be a discussion of the non-invasive determination of the viscosity of a non-Newtonian fluid in laminar pipe flow over the range of shear rates present in the pipe. The procedure used requires knowledge of the flow profile in and the pressure drop along a long straight run of pipe. The profile is determined by using a pulsed ultrasonic Doppler
David M, Pfund +3 more
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2012
The processing of pulse Doppler radar signals is commonly depicted as a sequence of stages known as the processing chain. Signal processing is applied to enhance the signal-to-noise ratio (SNR) to enhance detection performance, to discriminate between true targets and interference, clutter, or jamming, and to extract the desired information about ...
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The processing of pulse Doppler radar signals is commonly depicted as a sequence of stages known as the processing chain. Signal processing is applied to enhance the signal-to-noise ratio (SNR) to enhance detection performance, to discriminate between true targets and interference, clutter, or jamming, and to extract the desired information about ...
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1993
This chapter deals with Doppler techniques and their different applications for surveillance radar, multifunction radar and synthetic aperture radar. The chapter presents: an analysis of a simple pulse Doppler radar [fixed station, low pulse repetition frequency (PRF), no range ambiguity] (radar characteristics, power and spectra of clutter and target,
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This chapter deals with Doppler techniques and their different applications for surveillance radar, multifunction radar and synthetic aperture radar. The chapter presents: an analysis of a simple pulse Doppler radar [fixed station, low pulse repetition frequency (PRF), no range ambiguity] (radar characteristics, power and spectra of clutter and target,
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A method determining the Doppler angle in pulsed Doppler flowmeters
Proceedings of the Annual International Conference of the IEEE Engineering in Medicine and Biology Society, 1988At present, the most important problem of the ultrasonic Doppler blood flow measurement is Doppler angle, i.e., the angle between the flow vector and the sound beam direction. A method is proposed which uses identification of two successive echos in the analysis.
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A processor for pulse-doppler radar
IEEE Transactions on Electron Devices, 1976Methods are presented for combining charge-coupled device (CCD) and surface acoustic wave (SAW) techniques to advantage for processing coherent radar signals in order to extract target range and velocity information. Experiments have validated a scheme of combined discrete CCD's to form an analog store with orthogonal input and output sequencing ...
J.B.G. Roberts +3 more
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[Transcranial pulsed Doppler].
Journal de radiologie, 1993Transcranial Doppler ultrasonography is the only non invasive examination enabling the reliable measurement of the blood flow velocity in the intracranial arterial trunks. However, it cannot be constantly perfect. It is fully realized in about 10% of the patient.
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