scholarly journals A comparative study of four vector velocity estimation methods applied to flow imaging

2010 ◽  
Vol 3 (1) ◽  
pp. 225-233 ◽  
Author(s):  
Adrien Marion ◽  
Walid Aoudi ◽  
Adrian Basarab ◽  
Philippe Delachartre ◽  
Didier Vray
Keyword(s):  
Comparative Study ◽  
Velocity Estimation ◽  
Estimation Methods ◽  
Flow Imaging ◽  
Vector Velocity

Blood flow evaluation in high-frequency, 40MHz imaging: A comparative study of four vector velocity estimation methods

Ultrasonics ◽  
2010 ◽  
Vol 50 (7) ◽  
pp. 683-690 ◽  
Author(s):  
Adrien Marion ◽  
Walid Aoudi ◽  
Adrian Basarab ◽  
Philippe Delachartre ◽  
Didier Vray
Keyword(s):  
Blood Flow ◽  
Comparative Study ◽  
High Frequency ◽  
Velocity Estimation ◽  
Estimation Methods ◽  
Vector Velocity ◽  
Blood Flow Evaluation

scholarly journals Uncertainty comparison of velocity estimators for ultrasound flow imaging in narrow channels / Messunsicherheitsvergleich von Geschwindigkeitsschätzern der Ultraschallströmungsbildgebung in schmalen Kanälen

2019 ◽  
Vol 86 (s1) ◽  
pp. 7-11
Author(s):  
David Weik ◽  
Christian Kupsch ◽  
Richard Nauber ◽  
Lars Büttner ◽  
Jürgen Czarske
Keyword(s):  
Measurement Uncertainty ◽  
Liquid Metals ◽  
Ultrasound Image ◽  
Velocity Estimation ◽  
Estimation Methods ◽  
Flow Imaging ◽  
Lateral Velocity ◽  
Narrow Channels ◽  
Image Velocimetry ◽  
Future Work

AbstractUltrasound Imaging with a linear phased array allows measuring turbulent vector profiles in two dimension with two components (2D2C). This is interesting in narrow channels for the application in battery cells or research in magnetohydrodynamics (MHD), where the access to the opaque fluid is often restricted. There are two main velocity estimation methods applicable: the Ultrasound Doppler Velocimetry (UDV) or the Ultrasound Image Velocimetry (UIV). In this work, these methods were evaluated by their attainable measurement uncertainty for the application in narrow channels, where the acquisition of the lateral velocity component is crucial. With a calibration rig, UIV could achieve a total measurement uncertainty of 9.9% and UDV 17.6%. As UIV reaches a 44% lower measurement uncertainty, it is the preferential method to measure lateral flows in narrow channels. In future work, the calibration rig will be adapted to optimize and characterize the flow instrumentation in opaque liquid metals.

scholarly journals Bio-Inspired Covert Active Sonar Strategy

Sensors ◽  
2018 ◽  
Vol 18 (8) ◽  
pp. 2436 ◽  
Author(s):  
Jiajia Jiang ◽  
Xianquan Wang ◽  
Fajie Duan ◽  
Chunyue Li ◽  
Xiao Fu ◽  
...  
Keyword(s):  
Marine Mammals ◽  
Estimation Method ◽  
Sperm Whale ◽  
Waveform Design ◽  
Velocity Estimation ◽  
Estimation Methods ◽  
Range Resolution ◽  
Active Sonar ◽  
Ocean Noise ◽  
Underwater Target

The covertness of the active sonar is a very important issue and the sonar signal waveform design problem was studied to improve covertness of the system. Many marine mammals produce call pulses for communication and echolocation, and existing interception systems normally classify these biological signals as ocean noise and filter them out. Based on this, a bio-inspired covert active sonar strategy was proposed. The true, rather than man-made sperm whale, call pulses were used to serve as sonar waveforms so as to ensure the camouflage ability of sonar waveforms. A range and velocity measurement combination (RVMC) was designed by using two true sperm whale call pulses which had excellent range resolution (RR) and large Doppler tolerance (DT). The range and velocity estimation methods were developed based on the RVMC. In the sonar receiver, the correlation technology was used to confirm the start and end time of sonar signals and their echoes, and then based on the developed range and velocity estimation method, the range and velocity of the underwater target were obtained. Then, the RVMC was embedded into the true sperm whale call-train to improve the camouflage ability of the sonar signal-train. Finally, experiment results were provided to verify the performance of the proposed method.

Comparative study of brain deformation estimation methods

2006 ◽  
Author(s):  
Fenghong Liu ◽  
Keith D. Paulsen ◽  
Karen E. Lunn ◽  
Hai Sun ◽  
Alexander Hartov ◽  
...  
Keyword(s):  
Comparative Study ◽  
Estimation Methods ◽  
Brain Deformation

A Comparative Study of CIPN Symptom Estimation Methods Based on Machine Learning

2021 ◽  
Author(s):  
Satoki Hamanaka ◽  
Wataru Sasaki ◽  
Tadashi Okoshi ◽  
Jin Nakazawa ◽  
Kaori Yagasaki ◽  
...  
Keyword(s):  
Machine Learning ◽  
Comparative Study ◽  
Estimation Methods

scholarly journals Comparative study of methodologies for pulse wave velocity estimation

2008 ◽  
Vol 22 (10) ◽  
pp. 669-677 ◽  
Author(s):  
P Salvi ◽  
E Magnani ◽  
F Valbusa ◽  
D Agnoletti ◽  
C Alecu ◽  
...  
Keyword(s):  
Pulse Wave Velocity ◽  
Comparative Study ◽  
Wave Velocity ◽  
Pulse Wave ◽  
Velocity Estimation

scholarly journals Fixed Echo Rejection in Sodar Using Noncoherent Matched Filter Detection and Gaussian Mixture Model–Based Postprocessing

2019 ◽  
Vol 36 (1) ◽  
pp. 3-16
Author(s):  
Paul Kendrick ◽  
Sabine von Hünerbein
Keyword(s):  
Radial Velocity ◽  
Matched Filter ◽  
Gaussian Mixture ◽  
Urban Environments ◽  
Velocity Estimation ◽  
Estimation Methods ◽  
Chirp Pulse ◽  
Signal Processing Algorithm ◽  
Doppler Sodar ◽  
Wind Profiles

AbstractDoppler sodar is a technology used for acoustic-based remote sensing of the lower planetary boundary layer. Sodars are often used to measure wind profiles; however, they suffer from problems caused by noise (both acoustic and electrical) and echoes from fixed objects, which can bias radial velocity estimates. An experimental bistatic sodar was developed with 64 independent channels. The device enables flexible beamforming; beams can be tilted at the same angle irrelevant of frequency, a limitation in most commercial devices. This paper presents an alternative sodar signal-processing algorithm for wind profiling using a multifrequency stepped-chirp pulse. A noncoherent matched filter was used to analyze returned signals. The noncoherent matched filter combines radial velocity estimates from multiple frequencies into a single optimization. To identify and separate sources of backscatter, noise, and fixed echoes, a stochastic pattern-recognition technique, Gaussian mixture modeling, was used to postprocess the noncoherent matched filter data. This method allowed the identification and separation of different stochastic processes. After identification, noise and fixed echo components were removed and a clean wind profile was produced. This technique was compared with traditional spectrum-based radial velocity estimation methods, and an improvement in the rejection of fixed echo components was demonstrated; this is one of the major limitations of sodar performance when located in complex terrain and urban environments.

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