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Related papers: Caract{\'e}risation d'une Source Diffuse {\`a} par…

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Methods currently in use for locating and characterising sources in radio interferometry maps are designed for processing images, and require interferometric maps to be preprocessed so as to resemble conventional images. We demonstrate a…

Instrumentation and Methods for Astrophysics · Physics 2018-12-26 Peter Hague , Haoyang Ye , Bojan Nikolic , Steve Gull

Sky models have been used in the past to calibrate individual low radio frequency telescopes. Here we generalize this approach from a single antenna to a two element interferometer and formulate the problem in a manner to allow us to…

Instrumentation and Methods for Astrophysics · Physics 2017-06-28 Divya Oberoi , Rohit Sharma , Alan E. E. Rogers

Radiative transfer coupled with highly realistic simulations of the solar atmosphere is routinely used to infer the physical properties underlying solar observations. Due to its computational efficiency, the method of short-characteristics…

Solar and Stellar Astrophysics · Physics 2018-04-17 Courtney L. Peck , Serena Criscuoli , Mark P. Rast

The shape of the curves defined by the counts of radio sources per unit area as a function of their flux density was one of the earliest cosmological probes. Radio source counts continue to be an area of interest, used to study the relative…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 Ian Heywood , Matt J. Jarvis , James J. Condon

We propose an interferometric scheme for the estimation of a linear combination with non-negative weights of an arbitrary number $M>1$ of unknown phase delays, distributed across an $M$-channel linear optical network, with…

Quantum Physics · Physics 2019-12-04 Dario Gatto , Paolo Facchi , Frank Narducci , Vincenzo Tamma

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

This paper proposes the combination of SAR and microwave reflection tomography for biomedical imaging applications. The proposed method can achieve accuracies of less than 5mm and does not suffer from instability during reconstruction.…

Medical Physics · Physics 2018-05-01 Kevin K. M. Chan , Daniel Oloumi , Pierre Boulanger , Karumudi Rambabu

We present an algorithm to estimate fast and accurate depth maps from light fields via a sparse set of depth edges and gradients. Our proposed approach is based around the idea that true depth edges are more sensitive than texture edges to…

Computer Vision and Pattern Recognition · Computer Science 2021-07-08 Numair Khan , Min H. Kim , James Tompkin

I discuss two-particle intensity interferometry as a method to extract from measured 1- and 2-particle momentum spectra information on the space-time geometry and dynamics of the particle emitting source. Particular attention is given to…

Nuclear Theory · Physics 2007-05-23 Ulrich Heinz

We present a method for subtracting point sources from interferometric radio images via forward modeling of the instrument response and involving an algebraic nonlinear minimization. The method is applied to simulated maps of the Murchison…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-20 G. Bernardi , D. A. Mitchell , S. M. Ord , L. J. Greenhill , B. Pindor , R. B. Wayth , J. S. B. Wyithe

Statistical properties of ensembles of random density matrices are investigated. We compute traces and von Neumann entropies averaged over ensembles of random density matrices distributed according to the Bures measure. The eigenvalues of…

Quantum Physics · Physics 2009-11-10 Hans-Juergen Sommers , Karol Zyczkowski

Automated source extraction and parameterization represents a crucial challenge for the next-generation radio interferometer surveys, such as those performed with the Square Kilometre Array (SKA) and its precursors. In this paper we present…

Instrumentation and Methods for Astrophysics · Physics 2016-05-09 S. Riggi , A. Ingallinera , P. Leto , F. Cavallaro , F. Bufano , F. Schillirò , C. Trigilio , G. Umana , C. S. Buemi , R. P. Norris

An interferometric technique is proposed for determining the spatial forms of the individual degrees of freedom through which a many body system can absorb energy from its environment. The method separates out the coherent excitations…

Quantum Physics · Physics 2017-08-30 S. Withington , C. N. Thomas , D. J. Goldie

Priors are essential for reconstructing images from noisy and/or incomplete measurements. The choice of the prior determines both the quality and uncertainty of recovered images. We propose turning score-based diffusion models into…

Computer Vision and Pattern Recognition · Computer Science 2023-08-30 Berthy T. Feng , Jamie Smith , Michael Rubinstein , Huiwen Chang , Katherine L. Bouman , William T. Freeman

Beamforming is an imaging tool for the investigation of aeroacoustic phenomena and results in high dimensional data that is broken down to spectra by integrating spatial Regions Of Interest. This paper presents two methods that enable the…

Sound · Computer Science 2021-09-29 Armin Goudarzi , Carsten Spehr , Steffen Herbold

Collecting and analysing X-ray photons over either spatial or temporal scales encompassing varying optical depth values requires knowledge about the optical depth distribution. In the case of sufficiently broad optical depth distribution,…

Instrumentation and Methods for Astrophysics · Physics 2022-03-16 Nicola Locatelli , Gabriele Ponti , Stefano Bianchi

We study an inverse problem for the wave equation where localized wave sources in random scattering media are to be determined from time resolved measurements of the waves at an array of receivers. The sources are far from the array, so the…

Mathematical Physics · Physics 2016-07-18 Liliana Borcea , Ilker Kocyigit

We present a novel method that allows for measuring the quality of diffusion-weighted MR images dependent on the image resolution and the image noise. For this purpose, we introduce a new thresholding technique so that noise and the signal…

Computer Vision and Pattern Recognition · Computer Science 2011-05-10 Jan Klein , Sebastiano Barbieri , Miriam H. A. Bauer , Christopher Nimsky , Horst K. Hahn

Interferometers are widely used in imaging technologies to achieve enhanced spatial resolution, but require that the incoming photons be indistinguishable. In previous work, we built and analyzed color erasure detectors which expand the…

We study the measurement of transverse diffusion through beam echoes. We revisit earlier observations of echoes in RHIC and apply an updated theoretical model to these measurements. We consider three possible models for the diffusion…

Accelerator Physics · Physics 2017-02-01 Tanaji Sen , Wolfram Fischer