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We describe an algorithm for the extraction of the angular power spectrum of an intensity field, such as the cosmic microwave background (CMB), from interferometer data. This new method, based on the gridding of interferometer visibilities…

Wavefront shaping systems aim to image deep into scattering tissue by reshaping incoming and outgoing light to correct aberrations caused by tissue inhomogeneity However, the desired modulation depends on the unknown tissue structure and…

Optics · Physics 2026-01-14 Sagi Monin , Marina Alterman , Anat Levin

Radio-frequency interference (RFI) presents a significant obstacle to current radio interferometry experiments aimed at the Epoch of Reionization. RFI contamination is often several orders of magnitude brighter than the astrophysical…

Instrumentation and Methods for Astrophysics · Physics 2025-03-05 Jade M. Ducharme , Jonathan C. Pober

Complex object wave recovery from single-shot interference pattern is an important practical problem in interferometry and digital holography. The most popular single-shot interferogram analysis method involves Fourier filtering of…

Image and Video Processing · Electrical Eng. & Systems 2019-06-28 Sunaina , Mansi Butola , Kedar Khare

Interferometric phase (InPhase) imaging is an important part of many present-day coherent imaging technologies. Often in such imaging techniques, the acquired images, known as interferograms, suffer from two major degradations: 1) phase…

Signal Processing · Electrical Eng. & Systems 2019-11-25 Joshin P. Krishnan , Mário A. T. Figueiredo , José M. Bioucas-Dias

Dark-field imaging based on grating interferometry is an emerging X-ray modality in medical imaging, which is particularly capable of providing complementary diagnostic information by visualizing the microstructural properties of lung…

Medical Physics · Physics 2026-05-29 Longchao Men , Peiyuan Guo , Jincheng Lu , Yan Xu , Hongxia Yin , Zhenchang Wang , Li Zhang , Zhentian Wang

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

As Part I of a paper series showcasing a new imaging framework, we consider the recently proposed unconstrained Sparsity Averaging Reweighted Analysis (uSARA) optimisation algorithm for wide-field, high-resolution, high-dynamic range,…

Instrumentation and Methods for Astrophysics · Physics 2023-09-11 Amanda G. Wilber , Arwa Dabbech , Adrian Jackson , Yves Wiaux

The Gridding algorithm has shown great utility for reconstructing images from non-uniformly spaced samples in the Fourier domain in several imaging modalities. Due to the non-uniform spacing, some correction for the variable density of the…

Image and Video Processing · Electrical Eng. & Systems 2021-06-17 Nicholas Dwork , Daniel O'Connor , Ethan M. I. Johnson , Corey A. Baron , Jeremy W. Gordon , John M. Pauly , Peder E. Z. Larson

The Wide-Field InfraRed Space Telescope (WFIRST) will be capable of delivering precise astrometry for faint sources over the enormous field of view of its main camera, the Wide-Field Imager (WFI). This unprecedented combination will be…

As ground-based all-sky astronomical surveys will gather millions of images in the coming years, a critical requirement emerges for the development of fast deconvolution algorithms capable of efficiently improving the spatial resolution of…

Instrumentation and Methods for Astrophysics · Physics 2024-07-31 Utsav Akhaury , Pascale Jablonka , Jean-Luc Starck , Frédéric Courbin

A host of new low-frequency radio telescopes seek to measure the 21-cm transition of neutral hydrogen from the early universe. These telescopes have the potential to directly probe star and galaxy formation at redshifts $20 \gtrsim z…

Grazing incidence mirrors for X-ray astronomy are usually designed in the parabola-hyperbola (Wolter I) configuration. This design allows for optimal images on-axis, which however degrade rapidly with the off-axis angle. Mirror surfaces…

Astrophysics · Physics 2009-11-06 Paolo Conconi , Sergio Campana

Radio interferometric imaging aims to estimate an unknown sky intensity image from degraded observations, acquired through an antenna array. In the theoretical case of a perfectly calibrated array, it has been shown that solving the…

Instrumentation and Methods for Astrophysics · Physics 2017-07-25 Audrey Repetti , Jasleen Birdi , Arwa Dabbech , Yves Wiaux

A new method for the reconstruction of the projected mass distribution of clusters of galaxies from the image distortion of background galaxies is discussed. This method is essentially equivalent to the one we developed previously, i.e.,…

Astrophysics · Physics 2007-05-23 Stella Seitz , Peter Schneider

The deconvolution, or cleaning, of radio interferometric images often involves computing model visibilities from a list of clean components, in order that the contribution from the model can be subtracted from the observed visibilities.…

Instrumentation and Methods for Astrophysics · Physics 2019-09-10 Chris J. Skipper , Anna M. M. Scaife , Jason D. McEwen

Numerous linear and non-linear data-detection and precoding algorithms for wideband massive multi-user (MU) multiple-input multiple-output (MIMO) wireless systems that rely on orthogonal frequency-division multiplexing (OFDM) or…

Information Theory · Computer Science 2018-11-12 Charles Jeon , Zequn Li , Christoph Studer

This paper presents a novel signal processing technique, coined grid hopping, as well as an active multistatic Frequency-Modulated Continuous Wave (FMCW) radar system designed to evaluate its performance. The design of grid hopping is…

Signal Processing · Electrical Eng. & Systems 2023-08-01 Gilles Monnoyer , Thomas Feuillen , Maxime Drouguet , Laurent Jacques , Luc Vandendorpe

We consider a troublesome form of non-isoplanatism in synthesis radio telescopes: non-coplanar baselines. We present a novel interpretation of the non-coplanar baselines effect as being due to differential Fresnel diffraction in the…

Astrophysics · Physics 2009-11-13 T. J. Cornwell , K. Golap , S. Bhatnagar

We present an analytical description and an experimental realization of interscale mixing microscopy, a diffraction-based imaging technique that is capable of detecting wavelength/10 objects in far-field measurements with both coherent and…

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