In this paper, an overview of Doppler ultrasound quality assurance (QA) testing will be presented in three sections. The first section will review the different Doppler ultrasound parameters recommended by professional bodies for use in QA protocols. The second section will include an evaluation and critique of the main test devices used to assess Doppler performance, while the final section of...

This paper introduces a new and novel radar interferometry based on Doppler synthetic aperture radar (Doppler-SAR) paradigm. Conventional SAR interferometry relies on wideband transmitted waveforms to obtain high range resolution. Topography of a surface is directly related to the range difference between two antennas configured at different positions. Doppler-SAR is a novel imaging modality th...

nowadays, radar systems have many applications and radar imaging is one of the most important of these applications. inverse synthetic aperture radar (isar) is used to form an image from moving targets. conventional methods use fourier transform to retrieve doppler information. however, because of maneuvering of the target, the doppler spectrum becomes time-varying and the image is blurred. joi...

the radars that use medium prf, have either range ambiguity or doppler ambiguity, but these ambiguities can be resolved with selecting a prf set. avoiding ghost targets detection and minimizing blind zones are two important points that we should consider in targets detection. then, using this set, coincident algorithm and clustering the closely detected points, we resolve ambiguity and detect t...

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. In the paper, the micro-Doppler effect in radar is introduced and the mathe...

In current Doppler blood flow studies, the low Doppler shift frequencies of high energy generated by the wall motion are purposely filtered out. Since these low Doppler shift frequencies are produced by the contracting myocardium, they are expected to contain potential information for the assessment of myocardial properties. Early descriptions of directional pulsed Doppler tissue imaging (DTI) ...

The Doppler effect, which occurs on the reflection of ultrasound from moving blood or tissue, is observed as a shift in frequency of the reflected ultrasound from that of the incident ultrasound. This Doppler shift has been widely used in clinical practice as a means of measuring blood velocity. Two types of Doppler Imaging are often discussed as facilities on ultrasonic scanners, namely Colour...

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In the formation of range-Doppler images, transient interference can result in Doppler-streak artifacts. These Doppler-streaks hinder the utility of the range-Doppler image and may obscure moving targets of interest. This paper describes a method for pre-processing the IQ data to substantially attenuate Doppler streaks in the subsequently formed range-Doppler images. The method consists of deco...