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We present for the first time Very-Long-Baseline Interferometry images of the radio galaxy Cygnus A at the frequency of $86$ $\rm GHz$. Thanks to the high spatial resolution of only ${\sim}200$ Schwarzschild radii ($R_{\bf S}$), such…

High Energy Astrophysical Phenomena · Physics 2016-03-30 B. Boccardi , T. P. Krichbaum , U. Bach , M. Bremer , J. A. Zensus

The quality of the reconstructed photoacoustic image largely depends on the amount of photoacoustic (PA) boundary data available, which in turn is proportional to the number of detectors employed. In case of limited data (owing to less…

Image and Video Processing · Electrical Eng. & Systems 2020-01-20 Navchetan Awasthi , Rohit Pardasani , Sandeep Kumar Kalva , Manojit Pramanik , Phaneendra K. Yalavarthy

Searches for slow radio transients and variables have generally focused on extragalactic populations, and the basic parameters of Galactic populations remain poorly characterized. We present a large 3 GHz survey performed with the Allen…

Imaging by aperture synthesis from interferometric data is a well-known, but is a strong ill-posed inverse problem. Strong and faint radio sources can be imaged unambiguously using time and frequency integration to gather more Fourier…

Instrumentation and Methods for Astrophysics · Physics 2015-12-22 M. Jiang , J. N. Girard , J. -L. Starck , S. Corbel , C. Tasse

It has been shown in the past, that the six Doppler data streams obtained LISA configuration can be combined by appropriately delaying the data streams for cancelling the laser frequency noise. Raw laser noise is several orders of magnitude…

General Relativity and Quantum Cosmology · Physics 2017-08-23 K. Rajesh Nayak , A. Pai , S. V. Dhurandhar , J-Y. Vinet

Hyperspectral remote sensing images (HSIs) usually have high spectral resolution and low spatial resolution. Conversely, multispectral images (MSIs) usually have low spectral and high spatial resolutions. The problem of inferring images…

Computer Vision and Pattern Recognition · Computer Science 2015-06-23 Miguel Simões , José Bioucas-Dias , Luis B. Almeida , Jocelyn Chanussot

Radio interferometric imaging has long relied on the CLEAN algorithm, valued for its speed, robustness, and integration with calibration pipelines. However, next-generation facilities such as the ngVLA, SKA, and ALMAs Wideband Sensitivity…

Instrumentation and Methods for Astrophysics · Physics 2025-09-19 Hendrik Müller

Achieving high-resolution Direction of Arrival (DoA) recovery typically requires high Signal to Noise Ratio (SNR) and a sufficiently large number of snapshots. This paper presents NUV-DoA algorithm, that augments Bayesian sparse…

Signal Processing · Electrical Eng. & Systems 2023-12-27 Mengyuan Zhao , Guy Revach , Tirza Routtenberg , Nir Shlezinger

We propose a new technique to obtain super-resolution images with radio interferometer using sparse modeling. In standard radio interferometry, sampling of ($u$, $v$) is quite often incomplete and thus obtaining an image from observed…

Instrumentation and Methods for Astrophysics · Physics 2014-07-10 Mareki Honma , Kazunori Akiyama , Makoto Uemura , Shiro Ikeda

We report the results of interferometric observations of Centaurus A with the MID-infrared Interferometer (MIDI) at ESO's VLTI telescope array. The interferometric measurements are spectrally resolved (R = 30) in the wavelength range 8 to…

We examine the problem of selecting a small set of linear measurements for reconstructing high-dimensional signals. Well-established methods for optimizing such measurements include principal component analysis (PCA), independent component…

Computer Vision and Pattern Recognition · Computer Science 2025-08-06 Ling-Qi Zhang , Zahra Kadkhodaie , Eero P. Simoncelli , David H. Brainard

New generation of radio interferometers are envisaged to produce high quality, high dynamic range Stokes images of the observed sky from the corresponding under-sampled Fourier domain measurements. In practice, these measurements are…

Instrumentation and Methods for Astrophysics · Physics 2020-01-08 Jasleen Birdi , Audrey Repetti , Yves Wiaux

This paper presents a multilevel algorithm specifically designed for radio-interferometric imaging in astronomy. The proposed algorithm is used to solve the uSARA (unconstrained Sparsity Averaging Reweighting Analysis) formulation of this…

Optimization and Control · Mathematics 2024-03-21 Guillaume Lauga , Audrey Repetti , Elisa Riccietti , Nelly Pustelnik , Paulo Gonçalves , Yves Wiaux

We describe a "spatio-spectral" deconvolution algorithm for wide-band imaging in radio interferometry. In contrast with the existing multi-frequency reconstruction algorithms, the proposed method does not rely on a model of the…

Instrumentation and Methods for Astrophysics · Physics 2016-03-01 André Ferrari , Jérémy Deguignet , Chiara Ferrari , David Mary , Antony Schutz , Oleg Smirnov

Super-resolution aims at increasing the resolution and level of detail within an image. The current state of the art in general single-image super-resolution is held by NESRGAN+, which injects a Gaussian noise after each residual layer at…

Computer Vision and Pattern Recognition · Computer Science 2020-09-28 Baptiste Roziere , Nathanal Carraz Rakotonirina , Vlad Hosu , Andry Rasoanaivo , Hanhe Lin , Camille Couprie , Olivier Teytaud

Producing ultra-deep high-angular-resolution images with current and next-generation radio interferometers introduces significant computational challenges. In particular, the imaging is so demanding that processing large datasets,…

Instrumentation and Methods for Astrophysics · Physics 2025-01-14 J. M. G. H. J. de Jong , R. J. van Weeren , T. J. Dijkema , J. B. R. Oonk , H. J. A. Röttgering , F. Sweijen

In this work we introduce a new optimisation method called SAGA in the spirit of SAG, SDCA, MISO and SVRG, a set of recently proposed incremental gradient algorithms with fast linear convergence rates. SAGA improves on the theory behind SAG…

Machine Learning · Computer Science 2014-12-17 Aaron Defazio , Francis Bach , Simon Lacoste-Julien

In portable, 3-D, or ultra-fast ultrasound (US) imaging systems, there is an increasing demand to reconstruct high quality images from limited number of data. However, the existing solutions require either hardware changes or…

Computer Vision and Pattern Recognition · Computer Science 2017-10-31 Yeo Hun Yoon , Jong Chul Ye

We used the Karl G. Jansky Very Large Array (VLA) to image one primary beam area at 3 GHz with 8 arcsec FWHM resolution and 1.0 microJy/beam rms noise near the pointing center. The P(D) distribution from the central 10 arcmin of this…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-05 J. J. Condon , W. D. Cotton , E. B. Fomalont , K. I. Kellermann , N. Miller , R. A. Perley , D. Scott , T. Vernstrom , J. V. Wall

We address the problem of super-resolution frequency recovery using prior knowledge of the structure of a spectrally sparse, undersampled signal. In many applications of interest, some structure information about the signal spectrum is…

Information Theory · Computer Science 2014-09-08 Kumar Vijay Mishra , Myung Cho , Anton Kruger , Weiyu Xu