scholarly journals Achieving depth-independent lateral resolution in AR-PAM using the synthetic-aperture focusing technique

2021 ◽  
pp. 100328
Author(s):  
Rongkang Gao ◽  
Qiang Xue ◽  
Yaguang Ren ◽  
Hai Zhang ◽  
Liang Song ◽  
...  
Keyword(s):  
Synthetic Aperture ◽  
Lateral Resolution ◽  
Synthetic Aperture Focusing ◽  
Synthetic Aperture Focusing Technique

ULTRASONIC IMAGING SYSTEM USING A 2D ENVELOPE BEAMFORMING TECHNIQUE: IN-HOMOGENEITIES LOCATION

2004 ◽  
Vol 12 (04) ◽  
pp. 571-585
Author(s):  
L. MEDINA ◽  
E. MORENO
Keyword(s):  
Imaging System ◽  
Side Lobe ◽  
Ultrasonic Pulse ◽  
Image Resolution ◽  
Synthetic Aperture ◽  
Water Tank ◽  
Synthetic Aperture Focusing ◽  
Longitudinal Resolution ◽  
Synthetic Aperture Focusing Technique ◽  
Beamforming Technique

An algorithm has been developed to implement synthetic aperture focusing technique for B-scan. This is made at a several transmitter/receiver locations to form a map of ultrasonic reflectivity on the insonified region, considering the path travelled by the ultrasonic pulse from the transducer to the target and back again. To reconstruct the image, a time domain beam-former is applied to the envelope of the detected signals. This method minimizes the side-lobe amplitude and the restriction of λ/2 distance between two adjacent transducer positions can be neglected without loosing image resolution. The present work is focused on the location of the in-homogeneities, caused by the presence of a phantom immersed in a water tank. The results are presented when the distance between two adjacent transducer positions are varied from 0.5λ to 2.5λ showing that the longitudinal resolution is not affected but the lateral resolution becomes poorer when the distance is about 2λ. The error in the longitudinal location of in-homogeneities is within the minimum detectable distance of the system, while the lateral location error is increased when the distance between any two adjacent transducer positions is larger than 1.5λ.

Photoacoustic microscopy by scanning mirror-based synthetic aperture focusing technique

2015 ◽  
Vol 13 (10) ◽  
pp. 101101-101104 ◽  
Author(s):  
De Cai De Cai ◽  
Zhongfei Li Zhongfei Li ◽  
Sung-Liang Chen Sung-Liang Chen
Keyword(s):  
Synthetic Aperture ◽  
Photoacoustic Microscopy ◽  
Scanning Mirror ◽  
Synthetic Aperture Focusing ◽  
Synthetic Aperture Focusing Technique

Numerical simulation of internal defect imaging with the longitudinal wave generated by laser induced ultrasonic array

2020 ◽  
pp. 2150103
Author(s):  
Hao Sui ◽  
Kesi Li ◽  
Zhenyu Zhu ◽  
Le Cheng ◽  
Xiaorong Gao ◽  
...  
Keyword(s):  
Longitudinal Wave ◽  
Phased Arrays ◽  
Synthetic Aperture ◽  
Wave Component ◽  
The Finite Element Method ◽  
Internal Defect ◽  
Longitudinal Waves ◽  
Synthetic Aperture Focusing ◽  
Synthetic Aperture Focusing Technique ◽  
Defect Imaging

To verify the performance of longitudinal waves induced by laser phased arrays (LPA) for detection and quantitative evaluation in internal defects, the finite element method (FEM) is utilized to establish the models of LPA scanning processing. The interaction of longitudinal wave and internal defect is analyzed. Besides, the two components of the reflected longitudinal waves (the longitudinal wave component [Formula: see text] and the shear wave component [Formula: see text] are focused on the imaging of defects with the synthetic aperture focusing technique (SAFT) and total focusing method (TFM) algorithms. It shows that the imaging of internal sub-millimeter defect is obtained using the LPA. The defect size and location are simultaneously calculated, with the relative error being 6.7% and 2.9%, respectively. The proposed longitudinal wave-based LPA is a promising method for the imaging and evaluation of internal micro defects.

A matched model-based synthetic aperture focusing technique for acoustic microscopy

2019 ◽  
Vol 104 ◽  
pp. 51-57 ◽  
Author(s):  
Michael Wuest ◽  
Michael Schwarz ◽  
Johannes Eisenhart ◽  
Michael Nierla ◽  
Stefan J. Rupitsch
Keyword(s):  
Acoustic Microscopy ◽  
Synthetic Aperture ◽  
Model Based ◽  
Synthetic Aperture Focusing ◽  
Synthetic Aperture Focusing Technique
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