Green's function estimation from noise cross correlations

2016 ◽  
pp. 17-50
Author(s):  
Josselin Garnier ◽  
George Papanicolaou
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Function Estimation ◽  
Cross Correlations

Accuracy of Green's function estimation from correlation of diffuse elastic waves on thin plates

2019 ◽  
Vol 146 (5) ◽  
pp. 3505-3511
Author(s):  
Lynda Chehami ◽  
Emmanuel Moulin ◽  
Julien de Rosny ◽  
Claire Prada
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Elastic Waves ◽  
Thin Plates ◽  
Function Estimation

Green's function retrieval through cross-correlations in a two-dimensional complex reverberating medium

2014 ◽  
Vol 135 (3) ◽  
pp. 1034-1043 ◽  
Author(s):  
Andrea Colombi ◽  
Lapo Boschi ◽  
Philippe Roux ◽  
Michel Campillo
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Two Dimensional ◽  
Cross Correlations

scholarly journals Retrieval of a Green's Function with Reflections from Partly Coherent Waves Generated by a Wave Packet Using Cross Correlations

2013 ◽  
Vol 73 (1) ◽  
pp. 493-522 ◽  
Author(s):  
Maarten V. de Hoop ◽  
Josselin Garnier ◽  
Sean F. Holman ◽  
Knut Sølna
Keyword(s):  
Wave Packet ◽  
Green’S Function ◽  
Green's Function ◽  
Cross Correlations

Detection of near-surface defects in rails combining Green's function retrieval of ultrasonic diffuse fields and sign coherence factor imaging

2020 ◽  
Vol 62 (4) ◽  
pp. 216-221
Author(s):  
Haiyan Zhang ◽  
Mintao Shao ◽  
Guopeng Fan ◽  
Hui Zhang ◽  
Wenfa Zhu
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Surface Defects ◽  
Signal To Noise Ratio ◽  
Near Surface ◽  
Coherence Factor ◽  
Array Transducer ◽  
Diffuse Fields ◽  
Ultrasonic Phased Array ◽  
Cross Correlations

A method combining Green's function retrieval theory and sign coherence factor (SCF) imaging is presented to detect near-surface defects in rails. The defects are close to the ultrasonic phased array and near-surface acoustic information of defects is obscured by the non-linear effects of the initial wave signal in directly acquired responses. To overcome this problem, cross-correlations of the diffuse field signals captured by the array transducer are performed to reconstruct the Green's function. SCF imaging is used to further improve the spatial resolution and signal-to-noise ratio (SNR) of near-surface defects in rails. Experiments are conducted on two rails containing two and four defects, respectively. The results show that these defects can be clearly identified when using the reconstructed Green's function. However, the images of near-surface defects are masked and cannot be distinguished when using directly captured signals and total focus imaging. The proposed method reduces the background noise and allows for effective imaging of near-surface defects in rails.

Localization of acoustic sensors from passive Green's function estimation

2015 ◽  
Vol 138 (5) ◽  
pp. 3010-3018 ◽  
Author(s):  
Thibault Nowakowski ◽  
Laurent Daudet ◽  
Julien de Rosny
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Acoustic Sensors ◽  
Function Estimation

scholarly journals Beyond Receiver Functions: Green's Function Estimation by Transdimensional Inversion and Its Application to OBS Data

2019 ◽  
Vol 124 (2) ◽  
pp. 1944-1961 ◽  
Author(s):  
Takeshi Akuhara ◽  
Michael G. Bostock ◽  
Alexandre P. Plourde ◽  
Masanao Shinohara
Keyword(s):  
Green’S Function ◽  
Green's Function ◽  
Receiver Functions ◽  
Function Estimation ◽  
Obs Data

DIFFUSE FIELD INTERFEROMETRY FOR EXPERIMENTAL GREEN’S FUNCTION ESTIMATION AND DAMAGE DETECTION

2009 ◽  
Author(s):  
A. Duroux ◽  
J. Ayers ◽  
K. G. Sabra ◽  
M. Ruzzene ◽  
Donald O. Thompson ◽  
...  
Keyword(s):  
Damage Detection ◽  
Green’S Function ◽  
Green's Function ◽  
Function Estimation
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