Data-driven and calibration-free lamb wave source localization with sparse sensor arrays

Author(s):  
Joel B. Harley ◽  
Jose M. F. Moura
2015 ◽  
Author(s):  
Joel B. Harley ◽  
Chang Liu ◽  
Irving J. Oppenheim ◽  
David W. Greve ◽  
José M.F. Moura

2020 ◽  
pp. 147592172094519
Author(s):  
Shenxin Yin ◽  
Huapan Xiao ◽  
Zhiwen Cui ◽  
Tribikram Kundu

The acoustic source localization in 3D structures is a challenging task especially if the structure is heterogeneous. A large number of unknown parameters in a 3D heterogeneous structure require a large number of sensor arrays for accurate source localization. In this article, a localization technique is proposed using triangular pyramid shaped sensor clusters. The time difference of arrival of acoustic signals between different sensors of the clusters is analyzed to localize the acoustic source. It uses acoustic wave propagation information to rapidly localize the acoustic source. This rapid acoustic source localization technique works well for both homogeneous and heterogeneous media. It considers the refraction in heterogeneous media using Snell’s law. The proposed technique is verified experimentally and numerically. The experimental results show that the technique is effective for source localization in 3D homogeneous structures. Numerical results are generated by finite element modeling for both homogeneous and heterogeneous structures. The results show the reliability of the proposed technique. This technique helps to localize the acoustic source with only a few sensors and is indispensable for monitoring large 3D structures with monitoring equipment that can handle only a few sensors.


2020 ◽  
Author(s):  
Giovanni Angelo Meles ◽  
Lele Zhang ◽  
Jan Thorbecke ◽  
Kees Wapenaar ◽  
Evert Slob

<p>Seismic images provided by standard Reverse Time Migration are usually contaminated by artefacts associated with the migration of multiples.</p><p>Multiples can corrupt seismic images by producing both false negatives, i.e. by destructively interfering with primaries, and false positives, i.e. by focusing energy at unphysical interfaces. Free-surface multiples particularly affect seismic images resulting from marine data, while internal multiples strongly contaminate both land and marine data. Multiple prediction / primary synthesis methods are usually designed to operate on point source gathers, and can therefore be computationally  demanding when large problems, involving hundreds of gathers, are considered.</p><p>In this contribution, a new scheme for fully data-driven retrieval of primary responses of plane-wave sources is presented. The proposed scheme, based on convolutions and cross-correlations of the reflection response with itself,  extends a recently devised Marchenko point-sources primary retrieval method for to plane-wave source data. As a result, the presented algorithm allows fully data-driven synthesis of primary reflections associated with plane-wave source data. Once primary plane-wave responses are estimated, they are used for multiple-free imaging via standard reverse time migration. Numerical tests of increasing complexity demonstrate the potential of the proposed algorithm to produce multiple-free images only involving the migration of few datasets.</p><p>The plane-wave source primary synthesis algorithm discussed in this contribution could then be used as an initial and unexpensive processing step, potentially guiding more expensive target imaging techniques. Moreover, the method could be applied to large 3D problems for which standard methods are prohibitively expensive from a computational point of view.</p>


2017 ◽  
Vol 96 (8) ◽  
Author(s):  
Sizheng Ma ◽  
Zhoujian Cao ◽  
Chun-Yu Lin ◽  
Hsing-Po Pan ◽  
Hwei-Jang Yo

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