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Radio interferometry invariably suffers from an incomplete coverage of the spatial Fourier space, which leads to imaging artifacts. The current state-of-the-art technique is to create an image by Fourier-transforming the incomplete…

Instrumentation and Methods for Astrophysics · Physics 2024-12-19 F. Geyer , K. Schmidt , J. Kummer , M. Brüggen , H. W. Edler , D. Elsässer , F. Griese , A. Poggenpohl , L. Rustige , W. Rhode

Efficient estimators of Fourier-space statistics for large number of objects rely on Fast Fourier Transforms (FFTs), which are affected by aliasing from unresolved small scale modes due to the finite FFT grid. Aliasing takes the form of a…

Cosmology and Nongalactic Astrophysics · Physics 2017-10-09 Emiliano Sefusatti , Martin Crocce , Roman Scoccimarro , Hugh Couchman

Radio interferometers observe the Fourier space of the sky, at locations determined by the array geometry. Before a real space image is constructed by a Fourier transform, the data is weighted to improve the quality of reconstruction. Two…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Sarod Yatawatta

We propose a numerical interferometry method for identification of optical multiply-scattering systems when only intensity can be measured. Our method simplifies the calibration of optical transmission matrices from a quadratic to a linear…

Signal Processing · Electrical Eng. & Systems 2020-02-17 Sidharth Gupta , Rémi Gribonval , Laurent Daudet , Ivan Dokmanić

We solve the general problem of determining, through imaging, the three-dimensional positions of $N$ weak incoherent point-like emitters in an arbitrary spatial configuration. We show that a structured measurement strategy in which a linear…

Quantum Physics · Physics 2021-03-25 Cosmo Lupo , Zixin Huang , Pieter Kok

An extension may be proposed to the intensity interferometer of Hanbury Brown and Twiss to provide the Fourier phase measurement by the use of third-order intensity correlations. It is well known that interferometric reconstruction of…

Astrophysics · Physics 2008-06-14 B. E. Zhilyaev

The observation of neutron interference by using a crystal interferometer having a separate analyser opens the way to the construction and operation of interferometers with vast arm separation and length. Setting the design specifications…

Instrumentation and Detectors · Physics 2023-05-19 Carlo Paolo Sasso , Giovanni Mana , Enrico Massa

This paper provides a general introduction to the problem of image reconstruction from interferometric data. A simple model of the interferometric observables is given and the issues arising from sparse Fourier data are discussed. The…

Instrumentation and Methods for Astrophysics · Physics 2017-08-29 Éric Thiébaut , John Young

We devise a multiphoton interferometry scheme for sampling a quadratic function of a specific immanant for any submatrix of a unitary matrix and its row permutations. The full unitary matrix describes a passive, linear interferometer, and…

Quantum Physics · Physics 2020-05-12 Aeysha Khalique , Hubert de Guise , Barry C. Sanders

Astronomical optical interferometers sample the Fourier transform of the intensity distribution of a source at the observation wavelength. Because of rapid perturbations caused by atmospheric turbulence, the phases of the complex Fourier…

Instrumentation and Methods for Astrophysics · Physics 2014-10-07 Antony Schutz , André Ferrari , David Mary , Férréol Soulez , Éric Thiébaut , Martin Vannier

Infrared and visible image fusion has been a hot issue in image fusion. In this task, a fused image containing both the gradient and detailed texture information of visible images as well as the thermal radiation and highlighting targets of…

Computer Vision and Pattern Recognition · Computer Science 2020-09-04 Zixiang Zhao , Shuang Xu , Chunxia Zhang , Junmin Liu , Jiangshe Zhang

Based on diffraction theory and the propagation of the light, Fourier optics is a powerful tool allowing the estimation of a visible-range imaging system to transfer the spatial frequency components of an object. The analyses of the imaging…

General Physics · Physics 2018-06-05 Stephane Perrin , Paul Montgomery

Resolving sources beyond the diffraction limit is important in imaging, communications, and metrology. Current image-based methods of super-resolution require phase information (either of the source points or an added filter) and perfect…

Optics · Physics 2025-12-16 S. A. Wadood , Shaurya Aarav , Kevin Liang , Jason W Fleischer

Accurate beam modeling is important in many radio astronomy applications. In this paper, we focus on beam modeling for 21-cm intensity mapping experiments using radio interferometers, though the techniques also apply to single dish…

Instrumentation and Methods for Astrophysics · Physics 2025-09-16 Michael J. Wilensky , Philip Bull , Nicolas Fagnoni

The sparse layouts of radio interferometers result in an incomplete sampling of the sky in Fourier space which leads to artifacts in the reconstructed images. Cleaning these systematic effects is essential for the scientific use of…

Instrumentation and Methods for Astrophysics · Physics 2023-07-27 Kevin Schmidt , Felix Geyer , Stefan Fröse , Paul-Simon Blomenkamp , Marcus Brüggen , Francesco de Gasperin , Dominik Elsässer , Wolfgang Rhode

In this paper are reviewed various designs of advanced, multi-aperture optical systems dedicated to high angular resolution imaging or to the detection of exo-planets by nulling interferometry. A simple Fourier optics formalism applicable…

Optics · Physics 2016-01-20 Francois Henault

Bayesian image analysis has played a large role over the last 40+ years in solving problems in image noise-reduction, de-blurring, feature enhancement, and object detection. However, these problems can be complex and lead to computational…

Methodology · Statistics 2024-01-15 John Kornak , Karl Young , Eric Friedman

There are several solutions to code the signal arising from optical long baseline multi-aperture interferometers. In this paper,we focus on the {\bf non homothetic spatial coding scheme} (multiaxial) with the fringe pattern coded along one…

Astrophysics · Physics 2009-11-11 E. Tatulli , J. -B. LeBouquin

Astronomical optical interferometers (OI) sample the Fourier transform of the intensity distribution of a source at the observation wavelength. Because of rapid atmospheric perturbations, the phases of the complex Fourier samples…

Instrumentation and Methods for Astrophysics · Physics 2015-03-06 Antony Schutz , André Ferrari , David Mary , Eric Thiébaut , Ferréol Soulez

Radar interferometry usually exploits two complex-valued radar images with the same resolution to extract terrain elevation information. This paper considers the interferometry using two radar images with different resolutions, which we…

Information Theory · Computer Science 2018-12-14 Huizhang Yang , Chengzhi Chen , Shengyao Chen , Feng Xi , Zhong Liu
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