Experimental Marchenko focusing in a variable diameter sound wave tube

Becker, Theodor; Elison, Patrick; Manen, Dirk‐Jan van; Donahue, Carly M.; Greenhalgh, Stewart; Broggini, Filippo; Robertsson, Johan O. A.

doi:10.1190/segam2016-13866393.1

Cited by 9 publications

(6 citation statements)

References 5 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A third microphone is separated from the IBC system and is used to interrogate the wave field in V phy . The 1D character of the wave propagation in the waveguide was validated, and closely matching experimentally derived and theoretical reflection coefficients, as well as high signal-to-noise ratios, were observed in previous studies [43]. Data acquisition, IBC computation, and IBC emission for the 1D experiments were enabled using the portion of the full WaveLab system shown in Fig.…”

Section: Appendix A: 1d Experimental Setup In a Sound Wave Tubesupporting

confidence: 75%

Immersive Wave Propagation Experimentation: Physical Implementation and One-Dimensional Acoustic Results

et al. 2018

Self Cite

View full text Add to dashboard Cite

We present a fundamentally new approach to laboratory acoustic and seismic wave experimentation that enables full immersion of a physical wave propagation experiment within a virtual numerical environment. Using a recent theory of immersive boundary conditions that relies on measurements made on an inner closed surface of sensors, the output of numerous closely spaced sources around the physical domain is continuously varied in time and space. This allows waves to seamlessly propagate back and forth between both domains, without being affected by reflections at the boundaries between both domains, which enables us to virtually expand the size of the physical laboratory and operate at much lower frequencies than previously possible (sonic frequencies as low as 1 kHz). While immersive boundary conditions have been rigorously tested numerically, here we present the first proof of concept for their physical implementation with experimental results from a one-dimensional sound wave tube. These experiments demonstrate the performance and capabilities of immersive boundary conditions in canceling boundary reflections and accounting for long-range interactions with a virtual domain outside the physical experiment. Moreover, we introduce a unique high-performance acquisition, computation, and control system that will enable the real-time implementation of immersive boundary conditions in three dimensions. The system is capable of extrapolating wave fields recorded on 800 simultaneous inputs to 800 simultaneous outputs, through arbitrarily complex virtual background media with an extremely low total system latency of 200 μs. The laboratory allows studying a variety of long-standing problems and poorly understood aspects of wave physics and imaging. Moreover, such real-time immersive experimentation opens up exciting possibilities for the future of laboratory acoustic and seismic experiments and for fields such as active acoustic cloaking and holography.

show abstract

Section: Appendix A: 1d Experimental Setup In a Sound Wave Tubesupporting

confidence: 75%

Immersive Wave Propagation Experimentation: Physical Implementation and One-Dimensional Acoustic Results

et al. 2018

Self Cite

View full text Add to dashboard Cite

show abstract

“…Alternatively, to avoid inversion of the transmission response, the focusing function can be modelled directly, following a recursive Kirchhoff–Helmholtz wavefield extrapolation approach (Wapenaar ; Becker et al . ), starting with the focused field at

\partial {double-struckD}_{A}

and recursively moving upward. This gives

f_{1}^{+} false(boldx, x_{A}, t false)

and

f_{1}^{-} false(boldx, x_{A}, t false)

for all x above

\partial {double-struckD}_{A}

.…”

Section: Single‐sided Focusing In Two‐ and Three‐dimensional Mediamentioning

confidence: 99%

Review paper: Virtual sources and their responses, Part II: data‐driven single‐sided focusing

Wapenaar

Thorbecke

Neut

et al. 2017

Geophysical Prospecting

View full text Add to dashboard Cite

In Part I of this paper, we defined a focusing wave field as the time reversal of an observed point‐source response. We showed that emitting a time‐reversed field from a closed boundary yields a focal spot that acts as an isotropic virtual source. However, when emitting the field from an open boundary, the virtual source is highly directional and significant artefacts occur related to multiple scattering. The aim of this paper is to discuss a focusing wave field, which, when emitted into the medium from an open boundary, yields an isotropic virtual source and does not give rise to artefacts. We start the discussion from a horizontally layered medium and introduce the single‐sided focusing wave field in an intuitive way as an inverse filter. Next, we discuss single‐sided focusing in two‐dimensional and three‐dimensional inhomogeneous media and support the discussion with mathematical derivations. The focusing functions needed for single‐sided focusing can be retrieved from the single‐sided reflection response and an estimate of the direct arrivals between the focal point and the accessible boundary. The focal spot, obtained with this single‐sided data‐driven focusing method, acts as an isotropic virtual source, similar to that obtained by emitting a time‐reversed point‐source response from a closed boundary.

show abstract

“…Physical modeling is also used to test existing and develop new acquisition and processing technologies in a small-scale laboratory before implementing them in the field (Mo et al, 2015). Laboratory experiments offer the huge advantage of wellcontrolled conditions, possibly well-understood media, and almost perfect repeatability, which can facilitate the development of wave-based data processing and applications, including full waveform inversion (Bretaudeau et al, 2011;Isaac & Lawton, 1999;Dewangan et al, 2006), coda wave interferometry (Snieder et al, 2002;Hadziioannou et al, 2009;Larose et al, 2010;Niederleithinger et al, 2018), seismic tomography (Lo et al, 1988;De Cacqueray et al, 2013), and the Marchenko method (Becker et al, 2016;Mildner et al, 2017;Cui et al, 2018;da Costa Filho et al, 2018).…”

Section: Physical Modelingmentioning

confidence: 99%

Elastic immersive wave experimentation

Robertsson

Manen

2022

Geophysical Journal International

View full text Add to dashboard Cite

We describe an elastic wave propagation laboratory that enables a solid object to be artificially immersed within an extended (numerical) environment such that a physical wave propagation experiment carried out in the solid drives the propagation in the extended (numerical) environment and vice-versa. The underlying method of elastic immersive wave experimentation for such a laboratory involves deploying arrays of active multi-component sources at the traction-free surface of the solid (e.g., a cube of granitic rock). These sources are used to accomplish two tasks: (1) cancel outgoing waves, and (2) emit ingoing waves representing the first-order interactions between the physical and extended domains, computed using, e.g., a finite-difference (FD) method. Higher-order interactions can be built by alternately carrying out the processes for canceling the outgoing waves and the FD simulations for generating the ingoing waves. We validate the proposed iterative scheme for realizing elastic immersive wave experimentation using two-dimensional (2D) synthetic wave experiments.

show abstract

Experimental Marchenko focusing in a variable diameter sound wave tube

Cited by 9 publications

References 5 publications

Immersive Wave Propagation Experimentation: Physical Implementation and One-Dimensional Acoustic Results

Immersive Wave Propagation Experimentation: Physical Implementation and One-Dimensional Acoustic Results

Review paper: Virtual sources and their responses, Part II: data‐driven single‐sided focusing

Elastic immersive wave experimentation

Contact Info

Product

Resources

About