Detection of Velocity Perturbation Based on Coda Wave Interferometry

2014 ◽  
Author(s):  
J. Li ◽  
J. Tang ◽  
C. Sun ◽  
J. Xie ◽  
B. Fang ◽  
...  
Keyword(s):  
Coda Wave ◽  
Velocity Perturbation ◽  
Coda Wave Interferometry

scholarly journals Coda-wave interferometry and the Marchenko method

2020 ◽  
Author(s):  
Kees Wapenaar ◽  
Johno van IJsseldijk
Keyword(s):  
Fluid Flow ◽  
Propagation Velocity ◽  
High Sensitivity ◽  
Body Waves ◽  
Coda Wave ◽  
Local Perturbation ◽  
Local Velocity ◽  
Velocity Perturbation ◽  
Flow Process ◽  
Coda Wave Interferometry

<p>Coda-wave interferometry, introduced by Snieder and co-workers, employs the relative high sensitivity of the scattering coda in an acoustic or seismic response to time-lapse changes of the propagation velocity and/or structure. It has been successfully applied at many scales, ranging from inferring temperature changes in granite samples, via structural health monitoring of bridges, to monitoring the minute changes in the interior of a volcano prior to eruption. Whereas in most situations the velocity changes are assumed to take place in a large region, it has been shown that coda-wave interferometry can also be used to image a local perturbation of the propagation velocity or structure. The latter approach assumes diffuse waves and employs an array of receivers that surrounds the perturbation.</p><p>We investigate the application of coda-wave interferometry for monitoring of fluid-flow processes in aquifers, geothermal reservoirs, CO<sub>2</sub>-storage reservoirs and hydrocarbon reservoirs. In these applications the velocity perturbation is local, but the medium is probed with deterministic seismic body waves from the surface only. The location of the velocity perturbation is usually reasonably well known, but it is practically impossible to identify events in the coda that are directly related to the local perturbation. Recently we introduced the Marchenko method, which retrieves information about multiple scattering from reflection data at the surface in a data-driven way. Here we propose to use the Marchenko method to remove the response from the areas above and below the local velocity perturbation. In this way we isolate the scattering coda of the local velocity perturbation, which enables the application of coda-wave interferometry to monitor the fluid-flow process.</p>

scholarly journals Source Separation and Medium Change of Contained Chemical Explosions from Coda Wave Interferometry

2021 ◽  
Vol 1 (1) ◽  
pp. 3-10
Author(s):  
Sean R. Ford ◽  
William R. Walter
Keyword(s):  
Coda Wave ◽  
Velocity Perturbation ◽  
Spherical Region ◽  
Seismic Coda ◽  
Chemical Explosions ◽  
Medium Change ◽  
Physics Experiment ◽  
Coda Wave Interferometry ◽  
Source Physics ◽  
Chemical Explosion

Abstract Differences in the seismic coda of neighboring events can be used to investigate source location offsets and medium change with coda wave interferometry (CWI). We employ CWI to infer the known relative location between two chemical explosions in Phase I of the Source Physics Experiment (SPE). The inferred displacement between the first, SPE-1, and second, SPE-2, chemical explosion is between 6 and 18 m, with an expectation of 9.2 m, where the known separation is close to 9.4 m. We also employ CWI to find any velocity perturbation due to damage from SPE-2, by comparing its coda with the collocated third SPE chemical explosion, SPE-3. We find that damage due to SPE-2 must be confined to a spherical region with radius less than 10 m and velocity perturbation less than 25%.

Monitoring medium changes in an intraplate setting with coda wave interferometry

2013 ◽  
Author(s):  
Virginie D'Hour ◽  
Aderson F. do Nascimento ◽  
Heleno C. de Lima Neto ◽  
Joaquim M. Ferreira ◽  
Martin Schimmel
Keyword(s):  
Coda Wave ◽  
Coda Wave Interferometry

scholarly journals Sensitivity of Ultrasonic Coda Wave Interferometry to Material Damage—Observations from a Virtual Concrete Lab

Materials ◽  
2021 ◽  
Vol 14 (14) ◽  
pp. 4033
Author(s):  
Claudia Finger ◽  
Leslie Saydak ◽  
Giao Vu ◽  
Jithender J. Timothy ◽  
Günther Meschke ◽  
...  
Keyword(s):  
Elastic Moduli ◽  
Concrete Specimen ◽  
Coda Wave ◽  
Velocity Change ◽  
Damage Scenarios ◽  
Different Types ◽  
Source Signal ◽  
The Impact ◽  
Structural Scale ◽  
Coda Wave Interferometry

Ultrasonic measurements are used in civil engineering for structural health monitoring of concrete infrastructures. The late portion of the ultrasonic wavefield, the coda, is sensitive to small changes in the elastic moduli of the material. Coda Wave Interferometry (CWI) correlates these small changes in the coda with the wavefield recorded in intact, or unperturbed, concrete specimen to reveal the amount of velocity change that occurred. CWI has the potential to detect localized damages and global velocity reductions alike. In this study, the sensitivity of CWI to different types of concrete mesostructures and their damage levels is investigated numerically. Realistic numerical concrete models of concrete specimen are generated, and damage evolution is simulated using the discrete element method. In the virtual concrete lab, the simulated ultrasonic wavefield is propagated from one transducer using a realistic source signal and recorded at a second transducer. Different damage scenarios reveal a different slope in the decorrelation of waveforms with the observed reduction in velocities in the material. Finally, the impact and possible generalizations of the findings are discussed, and recommendations are given for a potential application of CWI in concrete at structural scale.

Monitoring cleaning cycles of fouled ducts using ultrasonic coda wave interferometry (CWI)

Ultrasonics ◽  
2019 ◽  
Vol 96 ◽  
pp. 253-260 ◽  
Author(s):  
B. Chen ◽  
D. Callens ◽  
P. Campistron ◽  
E. Moulin ◽  
P. Debreyne ◽  
...  
Keyword(s):  
Coda Wave ◽  
Coda Wave Interferometry

Using Ultrasonic Coda Wave Interferometry for Monitoring Stress‐Induced Changes in Concrete

2010 ◽  
Author(s):  
Parisa Shokouhi ◽  
Ernst Niederleithinger ◽  
Andreas Zoëga ◽  
Andreas Barner ◽  
Dieter Schöne
Keyword(s):  
Coda Wave ◽  
Induced Changes ◽  
Coda Wave Interferometry
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