scholarly journals Statistical Stability and Time-Reversal Imaging in Random Media

2004 ◽  
pp. 15-24 ◽  
Author(s):  
James G. Berryman ◽  
Liliana Borcea ◽  
George C. Papanicolaou ◽  
Chrysoula Tsogka
Keyword(s):  
Time Reversal ◽  
Random Media ◽  
Statistical Stability

Backscattering time‐reversal of acoustic waves in random media

1999 ◽  
Vol 105 (2) ◽  
pp. 956-956
Author(s):  
Arnaud Tourin ◽  
Arnaud Derode ◽  
Mathias Fink
Keyword(s):  
Time Reversal ◽  
Acoustic Waves ◽  
Random Media

The Computational Study of Microwave-Induced Thermo-Acoustic Tomography for Biologic Tissue Imaging Based on Pseudo-Spectrum Time Domain and Time Reversal Mirror Technique

2012 ◽  
Vol 195-196 ◽  
pp. 353-359 ◽  
Author(s):  
Guo Ping Chen ◽  
Zhi Qin Zhao ◽  
Qing H. Liu
Keyword(s):  
Time Domain ◽  
Time Reversal ◽  
Random Media ◽  
Imaging System ◽  
Malignant Tumors ◽  
Computational Study ◽  
Initial Pressure ◽  
Acoustic Tomography ◽  
Model Parameters ◽  
Time Reversal Mirror

Microwave-Induced Thermo-Acoustic Tomography (MITAT) own much concerns in recent years in biomedical imaging field. High contrast and resolution compared with conventional microwave or ultrasound imaging system especially for malignant tumors are outstanding characters of it. In this paper, the induced thermo-acoustic wave propagating in a mimic biologic tissue is simulated by numeric method Pseudo-Spectrum Time Domain (PSTD). Due to the excellent performance in noise-depress and the stability for the fluctuation of the model parameters, Time Reversal Mirror (TRM) imaging technique is studied computationally for the simulative received thermo-acoustic signals. Some thermo-acoustic objects with different initial pressure distribution are designed and imaged by TRM technique to represent the complex biologic tissue case in a random media. The quality of images generated by TRM technique based on PSTD method hints the potential of the MITAT technique.

Long distance time reversal and imaging in random media: Numerical simulations

2001 ◽  
Vol 110 (5) ◽  
pp. 2633-2633 ◽  
Author(s):  
Peter Blomgren ◽  
George Papanicolaou ◽  
Hongkai Zhao
Keyword(s):  
Numerical Simulations ◽  
Time Reversal ◽  
Random Media ◽  
Long Distance

scholarly journals Time Reversal for Dispersive Waves in Random Media

2004 ◽  
Vol 64 (5) ◽  
pp. 1810-1838 ◽  
Author(s):  
André Nachbin ◽  
Jean-Pierre Fouque ◽  
Josselin Garnier
Keyword(s):  
Time Reversal ◽  
Random Media ◽  
Dispersive Waves

scholarly journals Time reversal for classical waves in random media

2001 ◽  
Vol 333 (11) ◽  
pp. 1041-1046 ◽  
Author(s):  
Guillaume Bal ◽  
Leonid Ryzhik
Keyword(s):  
Time Reversal ◽  
Random Media ◽  
Classical Waves

NUMERICAL AND EXPERIMENTAL TIME-REVERSAL OF ACOUSTIC WAVES IN RANDOM MEDIA

2001 ◽  
Vol 09 (03) ◽  
pp. 993-1003 ◽  
Author(s):  
ARNAUD DERODE ◽  
MICKAËL TANTER ◽  
ARNAUD TOURIN ◽  
LAURENT SANDRIN ◽  
MATHIAS FINK
Keyword(s):  
Time Reversal ◽  
Acoustic Waves ◽  
Random Media ◽  
Initial Conditions ◽  
Classical Mechanics ◽  
High Sensitivity ◽  
Amount Of Information ◽  
Simulation Based ◽  
Initial Source ◽  
Time Invariant

In classical mechanics, a time-reversal experiment with a large number of particles is impossible. Because of the high sensitivity to initial conditions, one would need to resolve the positions and velocities of each particle with infinite accuracy. Thus, it would require an infinite amount of information, which is of course out of reach. In wave physics however, the amount of information required to describe a wave field is limited and depends on the shortest wavelength of the field. Thus we can propose an acoustic equivalent of the experiment we mentioned above. We start with a coherent transient pulse, let it propagate through a disordered highly scattering medium, then record the scattered field and time-reverse it: surprisingly, it travels back to its initial source, which is not predictable by usual theories for random media. Indeed, to study waves propagation in disordered media theoreticians, who find it difficult to deal with one realization of disorder, use concepts defined as an average over the realizations, which naturally leads to the diffusion approximation. But the corresponding equation is not time-reversal invariant and thus fails in describing our experiment. Then, to understand our experimental results and try to predict new ones, we have developed a finite elements simulation based on the real microscopic time-invariant equation of propagation. The experimental and numerical results are found to be in very good agreement.

Time Reversal and Refocusing in Random Media

2003 ◽  
Vol 63 (5) ◽  
pp. 1475-1498 ◽  
Author(s):  
Guillaume Bal ◽  
Leonid Ryzhik
Keyword(s):  
Time Reversal ◽  
Random Media
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