Time Reversal Acoustics

Time Reversal Acoustics

This book highlights time reversal acoustics, techniques based on the symmetry properties of acoustic fields.

Author: Woon Siong Gan

Publisher: Springer Nature

ISBN: 9789811632358

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Predictions of Narrow band Acoustic Time Reversal in the Shallow Ocean

Predictions of Narrow band Acoustic Time Reversal in the Shallow Ocean

2.2 Representative Environment In the study of acoustic propagation under water, an acoustic model of the ocean ... as a range-independent sound channel R speed of sound=1536 m/s Sound Source Mean Channel Depth = 75 m Time-Reversing ...

Author: Michael Robert Dungan

Publisher:

ISBN: UOM:39015049503504

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Page:

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Gauge Invariance Approach to Acoustic Fields

Gauge Invariance Approach to Acoustic Fields

Abstract First, introduction is followed by the theory of time reversal acoustics with the following coverage: time reversal acoustics and superresolution. The following applications of time reversal acoustics are given to medical ...

Author: Woon Siong Gan

Publisher: Springer

ISBN: 9789811387517

Category: Technology & Engineering

Page: 169

View: 964

This book highlights the symmetry properties of acoustic fields and describes the gauge invariance approach, which can be used to reveal those properties. Symmetry is the key theoretical framework of metamaterials, as has been demonstrated by the successful fabrication of acoustical metamaterials. The book first provides the necessary theoretical background, which includes the covariant derivative, the vector potential, and invariance in coordinate transformation. This is followed by descriptions of global gauge invariance (isotropy), and of local gauge invariance (anisotropy). Sections on time reversal symmetry, reflection invariance, and invariance of finite amplitude waves round out the coverage.
Categories: Technology & Engineering

Theoretical and Computational Acoustics 2001

Theoretical and Computational Acoustics 2001

Time Reversal Self - Adaptive Focusing in Anistropic Elastic Solid Medium Bixing Zhang and Chenghao Wang Institute of Acoustics , The Chinese Academy of Sciences , 100080 , Beijing , People's Republic of China Abstract In this paper ...

Author: Er-Chang Shang

Publisher: World Scientific

ISBN: 9812777369

Category: Technology & Engineering

Page: 691

View: 921

This book contains 67 papers presented at ICTCA2001. It includes three keynote addresses surveying the frontier developments in computational and theoretical acoustics. The papers cover aero-, seismo- and ocean acoustics, as well as ultrasonics. Computational methods, numerical simulation, theoretical analysis and experimental results are emphasized by different papers.The proceedings have been selected for coverage in: Index to Scientific & Technical Proceedings (ISTP CDROM version / ISI Proceedings)
Categories: Technology & Engineering

Acoustic Room De reverberation Using Time Reversal Acoustics

Acoustic Room De reverberation Using Time Reversal Acoustics

This thesis probes the performance of one-channel time-reversal acoustics in a chamber in terms of the geometry of the cavity.

Author: David W. Liddy

Publisher:

ISBN: 1423552385

Category:

Page: 63

View: 539

This thesis probes the performance of one-channel time-reversal acoustics in a chamber in terms of the geometry of the cavity. In particular, a rectangular chamber is compared to an enclosure that has a stadium shape. The mode structure in the rectangular cavity is highly symmetric, while it is highly irregular in the stadium-shaped cavity. Time- reversal acoustic techniques produce an improved focus in the latter. The focusing quality is determined as a function of frequency, time-reversal window size, and spatial extent. A scheme for encrypted acoustic communication, both in air and underwater, that uses multiple broadband signals with identical bandwidth, Hanning window source spectra, and center frequencies separated by half the bandwidth, allowing for null detection between adjacent signals, is successfully investigated.
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Acoustical Imaging

Acoustical Imaging

JWST175-c05 JWST175-Gan April 11, 2012 0:1 Printer Name: Yet to Come Acoustical Imaging: Techniques and Applications for Engineers time-reversal method inherently incorporates the effects of scattering and variation in propagation ...

Author: Woon Siong Gan

Publisher: John Wiley & Sons

ISBN: 9781119941712

Category: Technology & Engineering

Page: 440

View: 740

The technology of acoustical imaging has advanced rapidly over the last sixty years, and now represents a sophisticated technique applied to a wide range of fields including non-destructive testing, medical imaging, underwater imaging and SONAR, and geophysical exploration. Acoustical Imaging: Techniques and Applications for Engineers introduces the basic physics of acoustics and acoustical imaging, before progressing to more advanced topics such as 3D and 4D imaging, elasticity theory, gauge invariance property of acoustic equation of motion and acoustic metamaterials. The author draws together the different technologies in sonar, seismic and ultrasound imaging, highlighting the similarities between topic areas and their common underlying theory. Key features: Comprehensively covers all of the important applications of acoustical imaging. Introduces the gauge invariance property of acoustic equation of motion, with applications in the elastic constants of isotropic solids, time reversal acoustics, negative refraction, double negative acoustical metamaterial and acoustical cloaking. Contains up to date treatments on latest theories of sound propagation in random media, including statistical treatment and chaos theory. Includes a chapter devoted to new acoustics based on metamaterials, a field founded by the author, including a new theory of elasticity and new theory of sound propagation in solids and fluids and tremendous potential in several novel applications. Covers the hot topics on acoustical imaging including time reversal acoustics, negative refraction and acoustical cloaking. Acoustical Imaging: Techniques and Applications for Engineers is a comprehensive reference on acoustical imaging and forms a valuable resource for engineers, researchers, senior undergraduate and graduate students.
Categories: Technology & Engineering

New Acoustics Based on Metamaterials

New Acoustics Based on Metamaterials

there are two targets with different reflectivity illuminated by a short pulse, two wavefronts refocused on each target will be generated by the time-reversal of the echoes reflected from these targets. TRM produces two real acoustic ...

Author: Woon Siong Gan

Publisher: Springer

ISBN: 9789811063763

Category: Technology & Engineering

Page: 313

View: 759

This book highlights the acoustical metamaterials’ capability to manipulate the direction of sound propagation in solids which in turn control the scattering, diffraction and refraction, the three basic mechanisms of sound propagation in solids. This gives rise to several novel theories and applications and hence the name new acoustics. As an introduction, the book mentions that symmetry of acoustic fields is the theoretical framework of acoustical metamaterials. This is then followed by describing that acoustical metamaterials began with locally resonant sonic materials which ushered in the concept of negative acoustic parameters such as mass density and bulk modulus. This complies with form invariance of the acoustic equation of motion which again exemplifies the symmetry property of acoustic fields.
Categories: Technology & Engineering

Imaging of Complex Media with Acoustic and Seismic Waves

Imaging of Complex Media with Acoustic and Seismic Waves

In time-reversal acoustics [1,2,3,4] a signal is recorded by an array of transducers, time-reversed and then re-transmitted into the medium. The retransmitted signal propagates back through the same medium and refocuses on the source.

Author: Mathias Fink

Publisher: Springer Science & Business Media

ISBN: 9783540446804

Category: Science

Page: 339

View: 145

In this interdisciplinary book, leading experts in underwater acoustics, seismology, acoustic medical imaging and non-destructive testing present basic concepts as well as the recent advances in imaging. The different subjects tackled show significant similarities.
Categories: Science

Performance Analysis of an Acoustic Time Reversal System in Dynamic and Random Oceanic Environments

Performance Analysis of an Acoustic Time Reversal System in Dynamic and Random Oceanic Environments

Am . Encyclopedia of Acoustics , vol 1 , Ch . 48 , John Wiley & sons , 1997 . Fink , M. , Prada , C. , and Wu , F. , 1991 , “ Self - focusing with “ time reversal ' acoustic mirrors ” , Acoustical Imaging , vol 18 , Plenum Press ...

Author: Sunny Rajendra Khosla

Publisher:

ISBN: UOM:39015050164014

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Seismic Interferometry

Seismic Interferometry

SI164 ofthe closed time-reversal cavity: IEEE Transactions on Ultrasonics, Ferroelectrics, andFrequency Control, 39, 579–592. ——–, 1994, Time reversal focusing through a plane interface separating two fluids: Journal ofthe Acoustical ...

Author: Cornelis Pieter Arie Wapenaar

Publisher: SEG Books

ISBN: 9781560801504

Category: Science

Page: 628

View: 507

Shows that developments in seismic interferometry - the methodology of generating new seismic responses by crosscorrelation - have taken an enormous flight since the beginning of this century. In 2006, the editors of this volume compiled a supplement to Geophysics dedicated to this new branch of science. The 22 papers of the well-received supplement (recognized by one award for best paper and two honorable mentions for best paper in Geophysics and more than 100 citations in the first 20 months) form the basis for this reprint volume. The editors have added 50 papers from SEG and other journals, including Science, Physical Review, and Geophysical Research Letters. The book contains an editors' introduction with extensive references and chapters on seismic interferometry without equations, highlights of the history of seismic interferometry from 1968 until 2003, and a more detailed overview of the rapid developments since 2004. Seismic Interferometry is an invaluable source for researchers and students interested in the theory and applications of interferometry in geophysical exploration (seismic and EM), seismology, ultrasonics, and underwater acoustics.
Categories: Science

Quantum Chaos Y2K

Quantum Chaos Y2K

Mathias Fink 10 Rue Vauquelin, 75005 Paris, France Received October 9, 2000 Abstract The objective of this paper is to show that time-reversal invariance can be exploited in acoustics to accurately control wave propagation through ...

Author: Karl-Fredrik Berggren

Publisher: World Scientific

ISBN: 9789810247119

Category: Science

Page: 282

View: 250

Quantum chaos is becoming a very wide field that ranges from experiments to theoretical physics and purely mathematical issues. In view of this grand span, Nobel Symposium 116 focused on experiments and theory, and attempted to encourage interplay between them. There was emphasis on the interdisciplinary character of the subject, involving a broad range of subjects in physics, including condensed matter physics, nuclear physics, atomic physics and elementary particle physics. The physics involved in quantum chaos has much in common with acoustics, microwaves, optics, etc., and therefore the symposium also covered aspects of wave chaos in this broader sense. The program was structured according to the following areas: manifestations of classical chaos in quantum systems; transport phenomena; quantal spectra in terms of periodic orbits; semiclassical and random matrix approaches; quantum chaos in interacting systems; chaos and tunneling; wave-dynamic chaos. This important book constitutes the proceedings of the symposium.
Categories: Science

Quantum Chaos Y2K

Quantum Chaos Y2K

Mathias Fink 10 Rue Vauquelin, 75005 Paris, France Received October 9, 2000 Abstract The objective of this paper is to show that time-reversal invariance can be exploited in acoustics to accurately control wave propagation through ...

Author: Karl-Fredrik Berggren

Publisher: World Scientific

ISBN: 9789814490436

Category: Science

Page: 284

View: 856

Quantum chaos is becoming a very wide field that ranges from experiments to theoretical physics and purely mathematical issues. In view of this grand span, Nobel Symposium 116 focused on experiments and theory, and attempted to encourage interplay between them. There was emphasis on the interdisciplinary character of the subject, involving a broad range of subjects in physics, including condensed matter physics, nuclear physics, atomic physics and elementary particle physics. The physics involved in quantum chaos has much in common with acoustics, microwaves, optics, etc., and therefore the symposium also covered aspects of wave chaos in this broader sense. The program was structured according to the following areas: manifestations of classical chaos in quantum systems; transport phenomena; quantal spectra in terms of periodic orbits; semiclassical and random matrix approaches; quantum chaos in interacting systems; chaos and tunneling; wave-dynamic chaos. This important book constitutes the proceedings of the symposium. Contents: After-Dinner Speech (M C Gutzwiller)Spectral Twinkling: A New Example of Singularity-Dominated Strong Fluctuations (Summary) (M Berry)Ground State Spin and Coulomb Blockade Peak Motion in Chaotic Quantum Dots (J A Folk et al.)Quantum Chaos and Transport Phenomena in Quantum Dots (A S Sachrajda)Chaos in Quantum Ratchets (H Linke et al.)Non-Universality of Chaotic Classical Dynamics: Implications for Quantum Chaos (M Wilkinson)Chaos and Interactions in Quantum Dots (Y Alhassid)Stochastic Aspects of Many-Body Systems: The Embedded Gaussian Ensembles (H A Weidenmüller)Effect of Symmetry Breaking on Statistical Distributions (G E Mitchell & J F Shriner, Jr.)Quantum Chaos and Quantum Computers (D L Shepelyansky)Disorder and Quantum Chromodynamics — Non-Linear σ Models (T Guhr & T Wilke)Correlation Between Periodic Orbits and Their Rôle in Spectral Statistics (M Sieber & K Richter)Neutron Stars and Quantum Billiards (A Bulgac & P Magierski)Tunneling and Chaos (S Tomsovic)Relaxation and Fluctuations in Quantum Chaos (G Casati)Scars and Other Weak Localization Effects in Classically Chaotic Systems (E J Heller)Classically-Forbidden Processes in Photoabsorption Spectra (J B Delos et al.)Wave Dynamical Chaos: An Experimental Approach in Billiards (A Richter)Acoustic Chaos (C Ellegaard et al.)Wave-Chaotic Optical Resonators and Lasers (A D Stone)Angular Momentum Localization in Oval Billiards (J U Nöckel)Chaos and Time-Reversed Acoustics (M Fink)and other papers Readership: Quantum, nuclear, atomic, condensed matter and high energy physicists, as well as researchers in classical wave physics. Keywords:
Categories: Science

Broken Passivity and Time reversal symmetry Bounds in Acoustics Devices

Broken Passivity and Time reversal symmetry Bounds in Acoustics Devices

This work introduces an entirely new way to achieve highly directional sound beyond traditional techniques

Author: Curtis Paul Rasmussen

Publisher:

ISBN: OCLC:1268234076

Category:

Page: 234

View: 681

We collect information about the world through our senses, two of which, hearing and touch, are attuned to the mechanical vibrations travelling around us. Scientists and engineers have learned to control these acoustic waves, and in so doing they have opened new possibilities in how we interact with each other and the natural world. One area of rapid progress is acoustic metamaterials, which are architected structures that can shape sound waves in ways that go beyond what is possible with natural materials. Given the potential of these new materials, it is important to consider their limits and identify the underlying physical principles responsible for them. In this dissertation we examine limitations in the response of acoustic materials and devices due to passivity and time-reversal symmetry. An important constraint that arises due to time-reversal symmetry is reciprocity. Reciprocity must be broken to create devices that allow sound through in only one direction. This work explores acoustic nonreciprocity with particular attention to applications in surface acoustic wave devices and topological acoustic demonstrations. One way to achieve acoustic nonreciprocity is with fluid flow. Based on this technique, we present an acoustic Mach-Zehnder isolator and nonreciprocal leaky-wave antenna. A different but equally fundamental and important constraint in acoustics technology is the trade-off between the size, efficiency, and bandwidth of a small resonator. By considering arbitrary stored and radiated sound fields surrounding a compact source, we derive a theoretical lower bound on the quality factor of a passive acoustic radiator. This work discusses opportunities to overcome this constraint by considering active resonators. We experimentally demonstrate a three-fold bandwidth improvement to the passive case by synthesizing a non-Foster circuit load for a piezoelectric sonar transducer. By using a Green’s function approach and by connecting the physics of a disordered array to the statistical theory of random walks, we also explore the physics of near-zero-index materials, and leverage their unusual sound-matter interactions to enable robust and highly directive acoustic sources. This work introduces an entirely new way to achieve highly directional sound beyond traditional techniques
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Advances in Acoustic Microscopy

Advances in Acoustic Microscopy

Principles of Time Reversal Acoustics 5.2.1. Time Reversal of Ultrasonic Fields: Basic Principles Time reversal processing take advantage of the invariance of the wave equation under a time reversal operation.(1-3) This means that if we ...

Author: Andrew Briggs

Publisher: Springer Science & Business Media

ISBN: 9781461558514

Category: Science

Page: 264

View: 929

This is the second volume of Advances in Acoustic Microscopy. It continues the aim of presenting applications and developments of techniques that are related to high-resolution acoustic imaging. We are very grateful to the authors who have devoted considerable time to preparing these chapters, each of which describes a field of growing importance. Laboratories that have high-performance acoustic microscopes are frequently asked to examine samples for which the highest available resolution is not necessary, and the ability to penetrate opaque layers is more significant. Such applications can be thought of as bridging the gap be tween acoustic microscopy at low gigahertz frequencies, and on the one hand nondestructive testing of materials at low megahertz frequencies and on the other hand medical ultrasonic imaging at low megahertz frequencies. Commercial acoustic microscopes are becoming increasingly available and popular for such applications. We are therefore delighted to be able to begin the volume with chapters from each of those two fields. The first chapter, by Gabriele Pfannschmidt, describes uses of acoustic microscopy in the semiconductor industry. It provides a splendid balance to the opening chapter of Volume 1, which came from a national research center, being written from within a major European electronics industry itself. Dr Pfann schmidt describes the use of two quite different types of acoustic microscopes, and points out the advantages of each for specific purposes.
Categories: Science

Materials and Acoustics Handbook

Materials and Acoustics Handbook

[DER 95] A. DERODE, P. Roux, M. FINK, “Robust Acoustic time reversal with high order multiple scattering”, Physical Review Letters, Vol 75, 23, p 4206-4209, December 1995. [FIN 97] M. FINK, “Time reversed Acoustics”, Physics Today, 20, ...

Author: Michel Bruneau

Publisher: John Wiley & Sons

ISBN: 9781118622865

Category: Technology & Engineering

Page: 960

View: 523

Written by a group of acoustics and vibration specialists, this book studies the acoustic and vibrating phenomena that occur in diverse materials used for all kinds of purposes. The first part studies the fundamental aspects of propagation: analytical, numerical and experimental. The second part outlines industrial and medical applications. Covering a wide range of topics that associate materials science with acoustics, this will be of invaluable use to researchers, engineers, or practitioners in this field, as well as students in acoustics, physics, and mechanics.
Categories: Technology & Engineering

Springer Handbook of Acoustics

Springer Handbook of Acoustics

Ocean Time-Reversal Acoustics Phase conjugation, first demonstrated in nonlinear optics and its Fourier conjugate version, time reversal is a process that has recently implemented in ultrasonic laboratory acoustic experiments [5.44].

Author: Thomas Rossing

Publisher: Springer

ISBN: 9781493907557

Category: Science

Page: 1286

View: 148

Acoustics, the science of sound, has developed into a broad interdisciplinary field encompassing the academic disciplines of physics, engineering, psychology, speech, audiology, music, architecture, physiology, neuroscience and others. Here is an unparalleled modern handbook reflecting this richly interdisciplinary nature edited by one of the acknowledged masters in the field, Thomas Rossing. Researchers and students benefit from the comprehensive contents spanning: animal acoustics including infrasound and ultrasound, environmental noise control, music and human speech and singing, physiological and psychological acoustics, architectural acoustics, physical and engineering acoustics, medical acoustics and ocean acoustics. The Springer Handbook of Acoustics reviews the most important areas of acoustics, with emphasis on current research. The authors of the various chapters are all experts in their fields. Each chapter is richly illustrated with figures and tables. The latest research and applications are incorporated throughout, e.g. computer recognition and synthesis of speech, physiological acoustics, psychological acoustics, thermoacoustics, diagnostic imaging and therapeutic applications and acoustical oceanography. This new edition of the Handbook features over 11 revised and expanded chapters, new illustrations and two new chapters covering microphone arrays, acoustic metamaterials and acoustic emission. These improvements will make the handbook even more useful as a reference and a guide for researchers and students in every branch of acoustics. Praise for the first edition: "This treatise is a successful attempt to cover in one book the diverse field of acoustics, which ranges from physics to music and from formal mathematics to technological applications. ... It is this reviewer's opinion that a handbook like Rossing's, which covers the whole field of acoustics, serves a real purpose because it not only gives one a chance to see how one's specialty is covered but it also permits one to make a quick survey of other acoustical areas." (Leo Beranek, American Journal of Physics, Vol. 77 (12), December, 2009) "The Springer Handbook of Acoustics falls into that exceptional list. ...every physics department should have a copy available." (John L. Hubisz, The Physics Teacher, Vol. 48, March, 2010) "This handbook is an excellent addition to the acoustics literature. ... The handbook nicely covers both basics and advances in several areas of acoustics. Several chapters provide good mathematical depth, making the handbook useful as a research and technical resource. ...Overall, a very useful educational and research resource. Summing Up: Recommended. Upper-division undergraduates through professionals." (M. G. Prasad, CHOICE, Vol. 45 (5), January, 2008) "This book covers a wide range of topics and the inclusion of musical acoustics, computer and electronic music appeal to me (singer, song-writer, performer and recording studio co-owner). This handbook is probably well suited for an undergraduate-level introduction to an acoustics course. ... The wide range of topics, inclusion of music-related chapters, eye-pleasing presentations and other useful features make this a very good book to have on your shelf." (Tim Casey, International Journal of Acoustics and Vibration, Vol. 13 (1), 2008) "The Springer Handbook of Acoustics comprises 28 chapters written by 33 authors. The Handbook of Acoustics is useful as a source book for anyone who needs or wants to become familiar with the jargon and issues related to a specific subfield of acoustics ... ." (Robert I. Odom, Siam Review, Vol. 50 (3), 2008) The Springer Handbook of Acoustics reviews the most important areas of acoustics, with emphasis on current research. The authors of the various chapters are all experts in their fields. Each chapter is richly illustrated with figures and tables. The latest research and applications are incorporated throughout, e.g. computer recognition and synthesis of speech, physiological acoustics, psychological acoustics, thermoacoustics, diagnostic imaging and therapeutic applications and acoustical oceanography. This new edition of the Handbook features over 13 revised and expanded chapters, new illustrations and 3 new chapters covering microphone arrays, acoustic metamaterials and acoustic emission. These improvements will make the handbook even more useful as a reference and a guide for researchers and students in every branch of acoustics.
Categories: Science

Mathematical Modeling in Biomedical Imaging I

Mathematical Modeling in Biomedical Imaging I

M. FINK, Time-reversed acoustics, Scientific American, 281 (November), 1—97, 1999. 3. M. FINK, G. MONTALDO AND M. TANTER, Time-reversal acoustics in biomedical engineering, Annu. Rev. Biomed. Eng., 5, 465—497, 2003.

Author: Habib Ammari

Publisher: Springer Science & Business Media

ISBN: 9783642034435

Category: Mathematics

Page: 228

View: 543

This volume gives an introduction to a fascinating research area to applied mathematicians. It is devoted to providing the exposition of promising analytical and numerical techniques for solving challenging biomedical imaging problems, which trigger the investigation of interesting issues in various branches of mathematics.
Categories: Mathematics

Pressure Sensitivity Kernels Applied to Time reversal Acoustics

Pressure Sensitivity Kernels Applied to Time reversal Acoustics

Time-reversal is a method of focusing sound in the ocean that has found a variety of applications in recent years, ranging from underwater communications to biological stone destruction.

Author: Kaustubha Raghukumar

Publisher:

ISBN: OCLC:432313543

Category:

Page: 126

View: 998

Time-reversal is a method of focusing sound in the ocean that has found a variety of applications in recent years, ranging from underwater communications to biological stone destruction. In order to produce a focal spot, the time-reversal process first needs to acquire the Green's function between source and receiver. This Green's function is time-reversed and retransmitted in order to produce a spatio-temporal focal spot at the original source location. If the medium properties in between the source and receiver change between the acquisition of the Green's function and the subsequent retransmission, the quality of the focal spot can degrade or even disappear. However, the time-reversal focal spot has been found to be surprisingly robust to changes in medium properties, which are chiefly sound speed fluctuations in underwater acoustics. At 445 Hz, the focal spot was seen to persist for a week, while at 3.5 kHz, the focal spot persists for about an hour. Sensitivity kernels have the ability to linearly map sound speed perturbations to a perturbation of an acoustic parameter such as travel-time or pressure. Sensitivity kernels have a Fresnel-like interference pattern with regions of positive and negative sensitivities in the medium. Time-reversal, which causes different arrival paths to arrive at the same time, results in overlapping sensitivity kernels that leads to a net reduction in pressure sensitivity at the focal spot. Upon expressing the pressure at the focal spot in terms of sensitivity kernels, source transmissions are derived that are even more robust than time-reversal. The theory developed using pressure sensitivity kernels is tested on experimental data, along with an internal wave model, using various metrics. The linear limitations of the kernels are explored in the context of time-evolving Green's functions. The optimized source functions are then tested using experimental Green's functions and their behavior is seen to be in the right sense. Finally, thermistor chain data gathered during a similar experiment allowed for the testing of a 'synthetic aperture thermistor chain'. Temperature observations, presumably caused by displacements of a reference temperature profile, are inverted to provide an estimate of the background temperature profile.
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