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Related papers: WKB Across Caustics: The Screened-WKB Method

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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

A radio interferometer indirectly measures the intensity distribution of the sky over the celestial sphere. Since measurements are made over an irregularly sampled Fourier plane, synthesising an intensity image from interferometric…

Instrumentation and Methods for Astrophysics · Physics 2014-03-18 Daniel Muscat

Scattering hinders the passage of light through random media and consequently limits the usefulness of optical techniques for sensing and imaging. Thus, methods for increasing the transmission of light through such random media are of…

Optics · Physics 2014-06-23 Curtis Jin , Raj Rao Nadakuditi , Eric Michielssen , Stephen Rand

In this paper, we present a multiscale framework for solving the Helmholtz equation in heterogeneous media without scale separation and in the high frequency regime where the wavenumber $k$ can be large. The main innovation is that our…

Numerical Analysis · Mathematics 2022-10-21 Yifan Chen , Thomas Y. Hou , Yixuan Wang

The idea of ultra-wideband (UWB) communications for short ranges (up to a few tens of meters) has been around for nearly three decades. However, despite significant efforts by the industry, UWB deployment has not yet reached its predicted…

Signal Processing · Electrical Eng. & Systems 2025-09-10 Brian Nelson , Hussein Moradi , Behrouz Farhang-Boroujeny

The numerical simulation of wave propagation in semiclassical (high-frequency) problems is well known to pose a formidable challenge. In this work, a new phase-space approach for the numerical simulation of semiclassical wave propagation,…

Analysis of PDEs · Mathematics 2008-10-30 Agissilaos G. Athanassoulis

The state-of-the-art methods for estimating high-dimensional covariance matrices all shrink the eigenvalues of the sample covariance matrix towards a data-insensitive shrinkage target. The underlying shrinkage transformation is either…

Machine Learning · Statistics 2025-11-25 Man-Chung Yue , Yves Rychener , Daniel Kuhn , Viet Anh Nguyen

This paper investigates the distributionally robust filtering of signals generated by state-space models driven by exogenous disturbances with noisy observations in finite and infinite horizon scenarios. The exact joint probability…

Optimization and Control · Mathematics 2024-07-29 Taylan Kargin , Joudi Hajar , Vikrant Malik , Babak Hassibi

Wave propagation through waveguides, quantum wires or films with a modest amount of disorder is in the semi-ballistic regime when in the transversal direction(s) almost no scattering occurs, while in the long direction(s) there is so much…

Condensed Matter · Physics 2009-10-28 A. Mosk , Th. M. Nieuwenhuizen , C. Barnes

With the development of modern radio interferometers, wide-field continuum surveys have been planned and undertaken, for which accurate wide-field imaging methods are essential. Based on the widely-used W-stacking method, we propose a new…

Instrumentation and Methods for Astrophysics · Physics 2023-05-01 Haoyang Ye , Steve F. Gull , Sze M. Tan , Bojan Nikolic

We propose and demonstrate a new phase retrieval method for imaging through random media. Although methods to recover the Fourier amplitude through random distortions are well established, recovery of the Fourier phase has been a more…

Optics · Physics 2021-05-14 Byungjae Hwang , Taeseong Woo , Cheolwoo Ahn , Jung-Hoon Park

We analyse a linear lattice Boltzmann (LB) formulation for simulation of linear acoustic wave propagation in heterogeneous media. We employ the single-relaxation-time Bhatnagar-Gross-Krook (BGK) as well as the general multi-relaxation-time…

Computational Physics · Physics 2017-05-24 Dattaraj B. Dhuri , Shravan M. Hanasoge , Prasad Perlekar , Johan O. A. Robertsson

We generalize the invariant imbedding theory of the wave propagation and derive new invariant imbedding equations for the propagation of arbitrary number of coupled waves of any kind in arbitrarily-inhomogeneous stratified media, where the…

Optics · Physics 2009-11-10 Kihong Kim , Dong-Hun Lee , H. Lim

This paper focuses on radar waveform optimization for minimizing the Cram\'er-Rao bound (CRB) in a multiple-input multiple-output (MIMO) radar system. In contrast to conventional approaches relying on semi-definite programming (SDP) and…

Signal Processing · Electrical Eng. & Systems 2024-09-20 Xiaohua Zhou , Xu Du , Yijie Mao

Semiclassical approximations are implemented in the calculation of position and width of low energy resonances for radial barriers. The numerical integrations are delimited by t/T<<8, with t the period of a classical particle in the barrier…

Quantum Physics · Physics 2011-07-13 Nicolas Fernandez-Garcia , Oscar Rosas-Ortiz

We present a novel approach for solving numerically one-dimensional scattering problems and apply it for computing the emission probability of an ultracold atom interacting with an arbitrary field mode of a high-$Q$ cavity. Our method is…

Quantum Physics · Physics 2009-10-31 T. Bastin , E. Solano

We propose a new compressive imaging method for reconstructing 2D or 3D objects from their scattered wave-field measurements. Our method relies on a novel, nonlinear measurement model that can account for the multiple scattering phenomenon,…

Computer Vision and Pattern Recognition · Computer Science 2016-10-07 Hsiou-Yuan Liu , Ulugbek S. Kamilov , Dehong Liu , Hassan Mansour , Petros T. Boufounos

We present a new algorithm to perform wide-field radio interferometric image reconstruction, with exact non-coplanar correction, that scales to big-data. This algorithm allows us to image 2 billion visibilities on 50 nodes of a computing…

Instrumentation and Methods for Astrophysics · Physics 2019-03-20 Luke Pratley , Jason D. McEwen

Multiple scattering of waves in disordered media is a nightmare whether it be for detection or imaging purposes. The best approach so far to get rid of multiple scattering is optical coherence tomography. It basically combines confocal…

We propose and analyze a quasi-Monte Carlo (QMC) algorithm for efficient simulation of wave propagation modeled by the Helmholtz equation in a bounded region in which the refractive index is random and spatially heterogenous. Our focus is…

Numerical Analysis · Mathematics 2021-01-27 M. Ganesh , Frances Y. Kuo , Ian H. Sloan