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This paper presents a non-parametric method for 3-D imaging of natural volumes using Synthetic Aperture Radar tomography. This array processing-based technique aims at characterizing a spatially distributed density of incoherent sources,…

Signal Processing · Electrical Eng. & Systems 2025-03-18 Colin Cros , Laurent Ferro-Famil

A method is proposed for deriving the dispersion measure (related to the line-of-sight integrated free electron density) to high-redshift, powerful synchrotron radio sources by analysis of the temporal/spectral properties of the recorded…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-15 R. V. E. Lovelace , D. W. Richards

This article is devoted to the detection of parameters in anomalous diffusion from a single passive measurement. More precisely, we consider the simultaneous identification of coefficients as well as a time-dependent source term appearing…

Analysis of PDEs · Mathematics 2026-03-10 Maolin Deng , Ali Feizmohammadi , Bangti Jin , Yavar Kian

We derive the distribution of interferometric visibility for a source exhibiting strong diffractive scintillation, with particular attention to spectral resolution at or near the Nyquist limit. We also account for arbitrary temporal…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Michael D. Johnson , Carl R. Gwinn

Interstellar scintillation can be used to probe transverse sizes of radio sources on scales inaccessible to the nominal resolution of any terrestrial telescope, e.g. $\lesssim 10^{-6}$ arc sec. Methodology is presented that exploits this…

Astrophysics · Physics 2007-05-23 J. M. Cordes

We derive the distribution of flux density of a compact source exhibiting strong diffractive scintillation. Our treatment accounts for arbitrary spectral averaging, spatially-extended source emission, and the possibility of intrinsic…

Instrumentation and Methods for Astrophysics · Physics 2012-08-09 Michael D. Johnson , Carl R. Gwinn

We present a rigorous description of the general problem of aperture photometry in high energy astrophysics photon-count images, in which the statistical noise model is Poisson, not Gaussian. We compute the full posterior probability…

Instrumentation and Methods for Astrophysics · Physics 2015-06-23 F. A. Primini , V. L. Kashyap

Transient radio signals of astrophysical origin present an avenue for studying the dynamic universe. With the next generation of radio interferometers being planned and built, there is great potential for detecting and studying large…

Instrumentation and Methods for Astrophysics · Physics 2015-05-27 Cathryn M. Trott , Randall B. Wayth , Jean-Pierre R. Macquart , Steven J. Tingay

We present an in-situ antenna characterization method and results for a "low-frequency" radio astronomy engineering prototype array, characterized over the 75-300 MHz frequency range. The presence of multiple cosmic radio sources,…

The dynamical evolution and radiative properties of luminous radio galaxies and quasars of the FRII type, are well understood. As a result, through the use of detailed modeling of the observed radio emission of such sources, one can…

Astrophysics of Galaxies · Physics 2021-12-08 Anna Wojtowicz , Lukasz Stawarz , Jerzy Machalski , Luisa Ostorero

A method for estimating the relative content of crystalline phases of a multiphase sample, based on probabilistic analysis of the intensities of the diffraction pattern reflexes, has been developed. The method is based on the introduction…

Materials Science · Physics 2023-11-21 S. V. Gabielkov , I. V. Zhyganiuk , A. D. Skorbun

For a sample of absolutely bounded i.i.d. random variables with a continuous density the cumulative distribution function of the sample variance is represented by a univariate integral over a Fourier series. If the density is a polynomial…

Statistics Theory · Mathematics 2008-10-10 T. Royen

Single-photon sources are a fundamental resource in quantum optics. The indistinguishability and purity of photons emitted from different sources are crucial (necessary, essential) properties for many quantum applications to ensure…

Quantum Physics · Physics 2020-07-15 Valérian Thiel , Alex O. C. Davis , Ke Sun , Peru D'Ornellas , Xian-Min Jin , Brian J. Smith

We propose a new method for separating superimposed sources using diffusion-based generative models. Our method relies only on separately trained statistical priors of independent sources to establish a new objective function guided by…

Machine Learning · Computer Science 2024-01-18 Tejas Jayashankar , Gary C. F. Lee , Alejandro Lancho , Amir Weiss , Yury Polyanskiy , Gregory W. Wornell

We review the effects of source size in interferometric observations and focus on the cases of very compact sources. If a source is extremely compact and/or weak (so it is not possible to detect signature of source structure in the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-04 I. Marti-Vidal , M. A. Perez-Torres , A. P. Lobanov

We present an algorithm capable of detecting diffuse, dim sources of any size in an astronomical image. These sources often defeat traditional methods for source finding, which expand regions around points of high intensity. Extended…

Instrumentation and Methods for Astrophysics · Physics 2016-01-05 T. Butler-Yeoman , M. Frean , C. P. Hollitt , D. W. Hogg , M. Johnston-Hollitt

We describe a simple test of the spatial uniformity of an ensemble of discrete events. Given an estimate for the point source luminosity function and an instrumental point spread function (PSF), a robust upper bound on the fractional point…

High Energy Astrophysical Phenomena · Physics 2010-05-12 Tracy R. Slatyer , Douglas P. Finkbeiner

In this paper, the author investigates the impact of external sources on the pattern formation and long-time behavior of concentration profiles of passive tracers in a two-dimensional shear flow. It is shown that a time-periodic…

chao-dyn · Physics 2007-05-23 Jinqiao Duan

Compressed sensing Synthetic Aperture Radar (SAR) image formation, formulated as an inverse problem and solved with traditional iterative optimization methods can be very computationally expensive. We investigate the use of denoising…

Image and Video Processing · Electrical Eng. & Systems 2025-04-25 Odysseas Pappas , Perla Mayo , Andrew Austin , Alin Achim

Long duration noisy-looking waveforms such as those obtained in randomly multiply scattering and reverberant media are complex; they resist direct interpretation. Nevertheless, such waveforms are sensitive to small changes in the source of…

Geophysics · Physics 2015-05-27 Richard L Weaver , Céline Hadziioannou , Eric Larose , Michel Campillo
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