English
Related papers

Related papers: Passive array imaging in random media

200 papers

An alternative approach to ultrasound computed tomography (USCT) for medical imaging is proposed, with the intent to (i) shorten acquisition time for devices with a large number of emitters, (ii) eliminate the calibration step, and (iii)…

Medical Physics · Physics 2022-01-25 Ines Elisa Ulrich , Christian Boehm , Andrea Zunino , Cyrill Bösch , Andreas Fichtner

In this paper, we use a straightforward numerical method to solve scattering models in one-dimensional lattices based on a tight-binding band structure. We do this by using the wave packet approach to scattering, which presents a more…

Physics Education · Physics 2022-07-06 M. Staelens , F. Marsiglio

We present measurements of the diffusion coefficient of ultrasound in strongly scattering three-dimensional (3D) disordered media using the dynamic coherent backscattering (CBS) effect. Our experiments measure the CBS of ultrasonic waves…

Disordered Systems and Neural Networks · Physics 2017-05-24 L. A. Cobus , B. A. van Tiggelen , A. Derode , J. H. Page

Non-invasive optical focusing inside scattering media is still a big challenge because inhomogeneous media scatter both incoming photons for focusing and outgoing photons for observation. Various approaches, utilizing non-linear…

Optics · Physics 2021-09-17 Dayan Li , Sujit Kumar Sahoo , Huy Quoc Lam , Dong Wang , Cuong Dang

We study two-dimensional wave propagation in materials whose properties vary periodically in one direction only. High order homogenization is carried out to derive a dispersive effective medium approximation. One-dimensional materials with…

Numerical Analysis · Mathematics 2014-09-16 Manuel Quezada de Luna , David I. Ketcheson

This work is concerned with optical imaging in strongly diffusive environments. We consider a typical setting in optical coherence tomography where a sample is probed by a collection of wavefields produced by a laser and propagating through…

Optics · Physics 2024-12-10 Randy Bartels , Olivier Pinaud , Maxine Varughese

Coherent diffractive imaging is a technique that recovers the sample image by numerically inverting its diffraction pattern. We propose a generalization of this method for the inversion of multi-wavelength data. Using this approach, we show…

Optics · Physics 2020-05-08 Erik Malm , Edwin Fohtung , Anders Mikkelsen

The development of efficient and accurate reconstruction methods is an important aspect of tomographic imaging. In this article, we address this issue for photoacoustic tomography. To this aim, we use models for acoustic wave propagation…

Numerical Analysis · Mathematics 2017-11-22 Markus Haltmeier , Richard Kowar , Linh V. Nguyen

Light propagation in materials with microscopic inhomogeneities is affected by scattering. In scattering materials, such as powders, disordered metamaterials or biological tissue, multiple scattering on sub-wavelength particles makes light…

Disordered Systems and Neural Networks · Physics 2009-11-13 I. M. Vellekoop , A. P. Mosk

Optical focusing through/inside scattering media, like multimode fiber and biological tissues, has significant impact in biomedicine yet considered challenging due to strong scattering nature of light. Previously, promising progress has…

We introduce a new numerical method for solving time-harmonic acoustic scattering problems. The main focus is on plane waves scattered by smoothly varying material inhomogeneities. The proposed method works for any frequency $\omega$, but…

Numerical Analysis · Mathematics 2022-01-14 Anton Arnold , Sjoerd Geevers , Ilaria Perugia , Dmitry Ponomarev

Fluorescent imaging plays a critical role in a myriad of scientific endeavors, particularly in the biological sciences. Three-dimensional imaging of fluorescent intensity often requires serial data acquisition, that is voxel-by-voxel…

Optics · Physics 2015-10-27 Jeffrey J. Field , David G. Winters , Randy A. Bartels

Recently, sparsity-based algorithms are proposed for super-resolution spectrum estimation. However, to achieve adequately high resolution in real-world signal analysis, the dictionary atoms have to be close to each other in frequency,…

Machine Learning · Statistics 2015-06-05 Yiyuan She , Huanghuang Li , Jiangping Wang , Dapeng Wu

We propose an efficient method to estimate source power spectral densities (PSDs) in a multi-source reverberant environment using a spherical microphone array. The proposed method utilizes the spatial correlation between the spherical…

Sound · Computer Science 2018-05-21 Abdullah Fahim , Prasanga N. Samarasinghe , Thushara D. Abhayapala

When waves propagate through a strongly scattering medium the energy is transferred to the incoherent wave part by scattering. The wave intensity then forms a random speckle pattern seemingly without much useful information. However, a…

Optics · Physics 2018-02-23 Josselin Garnier , Knut Solna

Recently, the progress of learning-by-synthesis has proposed a training model for synthetic images, which can effectively reduce the cost of human and material resources. However, due to the different distribution of synthetic images…

Computer Vision and Pattern Recognition · Computer Science 2020-02-17 Yuxiao Yan , Yang Yan , Jinjia Peng , Huibing Wang , Xianping Fu

Estimating the sound absorption in situ relies on accurately describing the measured sound field. Evidence suggests that modeling the reflection of impinging spherical waves is important, especially for compact measurement systems. This…

Audio and Speech Processing · Electrical Eng. & Systems 2024-04-18 Eric Brandao , William Fonseca , Paulo Mareze , Carlos Resende , Gabriel Azzuz , Joao Pontalti , Efren Fernandez-Grande

Imaging through scattering and random media is an outstanding problem that to date has been tackled by either measuring the medium transmission matrix or exploiting linear correlations in the transmitted speckle patterns. However,…

Optics · Physics 2022-04-07 Ilya Starshynov , Alex Turpin , Philip Binner , Daniele Faccio

Ambient noise tomography relies on the assumption that the seismic wavefield is equipartitioned. In practice, ambient noise sources are spatially and temporally heterogeneous, producing biased estimates of the Green's function between…

Geophysics · Physics 2026-02-17 Sanket Narayan Bajad , Pushkar Bharadwaj , Pawan Bharadwaj

Imaging of the structure of single proteins or other biomolecules with atomic resolution would be enormously beneficial to structural biology. X-ray free-electron lasers generate highly intense and ultrashort x-ray pulses, providing a route…

Atomic Physics · Physics 2014-07-30 Jan Malte Slowik , Sang-Kil Son , Gopal Dixit , Zoltan Jurek , Robin Santra