Phase coherence imaging of grained materials

2011 ◽  
Vol 58 (5) ◽  
pp. 1006-1015 ◽  
Author(s):  
J Camacho ◽  
C Fritsch
Keyword(s):  
Phase Coherence ◽  
Coherence Imaging

Plane-wave phase-coherence imaging for NDE

2017 ◽  
Vol 87 ◽  
pp. 31-37 ◽  
Author(s):  
J.F. Cruza ◽  
J. Camacho ◽  
C. Fritsch
Keyword(s):  
Plane Wave ◽  
Phase Coherence ◽  
Wave Phase ◽  
Coherence Imaging

scholarly journals Phase Coherence Imaging: Principles, applications and current developments

2019 ◽  
Author(s):  
Jorge Camacho ◽  
Carlos Fritsch ◽  
Jorge Fernandez-Cruza ◽  
Montserrat Parrilla
Keyword(s):  
Phase Coherence ◽  
Coherence Imaging

Phase Coherence Imaging

2009 ◽  
Vol 56 (5) ◽  
pp. 958-974 ◽  
Author(s):  
J. Camacho ◽  
M. Parrilla ◽  
C. Fritsch
Keyword(s):  
Phase Coherence ◽  
Coherence Imaging

scholarly journals Phase Coherence Imaging for Near-Surface Defects in Rails Using Cross-Correlation of Ultrasonic Diffuse Fields

Metals ◽  
2019 ◽  
Vol 9 (8) ◽  
pp. 868
Author(s):  
Haiyan Zhang ◽  
Mintao Shao ◽  
Guopeng Fan ◽  
Hui Zhang ◽  
Wenfa Zhu ◽  
...  
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Cross Correlation ◽  
Phased Array ◽  
Surface Defects ◽  
Performance Indicator ◽  
Phase Coherence ◽  
Near Surface ◽  
Diffuse Fields ◽  
Coherence Imaging

In this paper, phase coherence imaging is proposed to improve spatial resolution and signal-to-noise ratio (SNR) of near-surface defects in rails using cross-correlation of ultrasonic diffuse fields. The direct signals acquired by the phased array are often obscured by nonlinear effects. Thus, the output image processed by conventional post-processing algorithms, like total focus method (TFM), has a blind zone close to the array. To overcome this problem, the diffuse fields, which contain spatial phase correlations, are applied to recover Green’s function. In addition, with the purpose of improving image quality, the Green’s function is further weighted by a special coherent factor, sign coherence factor (SCF), for grating and side lobes suppression. Experiments are conducted on two rails and data acquisition is completed by a commercial 32-element phased array. The quantitative performance comparison of TFM and SCF images is implemented in terms of the array performance indicator (API) and SNR. The results show that the API of SCF is significantly lower than that of TFM. As for SNR, SCF achieved a better SNR than that of TFM. The study in this paper provides an experimental reference for detecting near-surface defects in the rails.

GRAIN NOISE REDUCTION BY PHASE COHERENCE IMAGING

2010 ◽  
Author(s):  
J. Camacho ◽  
J. Brizuela ◽  
C. Fritsch ◽  
Donald O. Thompson ◽  
Dale E. Chimenti
Keyword(s):  
Noise Reduction ◽  
Phase Coherence ◽  
Coherence Imaging
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