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An unbiased method for improving the resolution of astronomical images is presented. The strategy at the core of this method is to establish a linear transformation between the recorded image and an improved image at some desirable…

Astrophysics · Physics 2016-08-30 F. P. Pijpers

Radio astronomy is currently thriving with new large ground-based radio telescopes coming online in preparation for the upcoming Square Kilometre Array (SKA). Facilities like LOFAR, MeerKAT/SKA, ASKAP/SKA, and the future SKA-LOW bring…

Instrumentation and Methods for Astrophysics · Physics 2023-08-02 Benjamin Naoto Chiche , Julien N. Girard , Joana Frontera-Pons , Arnaud Woiselle , Jean-Luc Starck

This work is concerned with the problem of blind source separation and its applications to imaging. We first establish a theoretical result that we stated in our previous article on imaging in diffusive environments. This result is a…

Numerical Analysis · Mathematics 2026-02-12 Randy Bartels , Olivier Pinaud

Interfering signals such as Radio Frequency Interference from ubiquitous satellite constellations are becoming an endemic problem in fields involving physical observations of the electromagnetic spectrum. To address this we propose a novel…

Instrumentation and Methods for Astrophysics · Physics 2024-02-20 S. A. K. Leeney , W. J. Handley , E. de Lera Acedo

A fruitful approach for solving signal deconvolution problems consists of resorting to a frame-based convex variational formulation. In this context, parallel proximal algorithms and related alternating direction methods of multipliers have…

Other Computer Science · Computer Science 2015-05-28 Nelly Pustelnik , Jean-Christophe Pesquet , Caroline Chaux

The spatial-frequency coverage of a radio interferometer is increased by combining samples acquired at different times and observing frequencies. However, astrophysical sources often contain complicated spatial structure that varies within…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 U. Rau

Upcoming and future neutral hydrogen Intensity Mapping surveys offer a great opportunity to constrain cosmology in the post-reionization Universe, provided a good accuracy is achieved in the separation between the strong foregrounds and the…

Cosmology and Nongalactic Astrophysics · Physics 2021-09-02 Siyambonga D. Matshawule , Marta Spinelli , Mario G. Santos , Sibonelo Ngobese

21 cm tomography is emerging as a promising probe of the cosmological dark ages and the epoch of reionization, as well as a tool for observational cosmology in general. However, serious sources of foreground contamination must be subtracted…

Astrophysics · Physics 2009-04-10 Adrian Liu , Max Tegmark , Matias Zaldarriaga

We describe a scalable distributed imaging algorithm framework for next-generation radio telescopes, managing the Fourier transform from apertures to sky (or vice versa) with a focus on minimising memory load, data transfers, and…

Instrumentation and Methods for Astrophysics · Physics 2024-07-17 Peter Wortmann , James Kent , Bojan Nikolic

The proposed next-generation Very Large Array (ngVLA) will enable the imaging of astronomical sources in unprecedented detail by providing an order of magnitude improvement in sensitivity and angular resolution compared with radio…

Solar and Stellar Astrophysics · Physics 2019-10-23 Kazunori Akiyama , Lynn D. Matthews

The ability to subtract foreground contamination from low-frequency observations is crucial to reveal the underlying 21 cm signal. The traditional line-of-sight methods can deal with the removal of diffuse emission and unresolved point…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Xiao-Chun Mao

Source separation or demixing is the process of extracting multiple components entangled within a signal. Contemporary signal processing presents a host of difficult source separation problems, from interference cancellation to background…

Information Theory · Computer Science 2015-06-17 Michael B. McCoy , Volkan Cevher , Quoc Tran Dinh , Afsaneh Asaei , Luca Baldassarre

The development of signal unmixing algorithms is essential for leveraging multimodal datasets acquired through a wide array of scientific imaging technologies, including hyperspectral or time-resolved acquisitions. In experimental physics,…

This paper demonstrates a practical method that can correct spatial varying blur from a set of images of the same object. The algorithm jointly estimates the object and local point spread functions~(PSF). The method prioritizes sections…

Image and Video Processing · Electrical Eng. & Systems 2020-11-04 Wouter van de Ketterij , Oleg Soloviev , Michel Verhaegen

Audio source separation is often achieved by estimating the magnitude spectrogram of each source, and then applying a phase recovery (or spectrogram inversion) algorithm to retrieve time-domain signals. Typically, spectrogram inversion is…

Sound · Computer Science 2023-07-03 Paul Magron , Tuomas Virtanen

Refraction by the atmosphere causes the positions of sources to depend on the airmass through which an observation was taken. This shift is dependent on the underlying spectral energy of the source and the filter or bandpass through which…

Instrumentation and Methods for Astrophysics · Physics 2019-05-01 Matthias Lee , Tamas Budavari , Ian Sullivan , Andrew Connolly

Two iterative techniques are described for decomposing a long-slit spectrum into the individual spectra of the point sources along the slit and the spectrum of the underlying background. One technique imposes the strong constraint that the…

Astrophysics · Physics 2009-11-07 L. B. Lucy , J. R. Walsh

Blind deconvolution is the problem of recovering a sharp image and a blur kernel from a noisy blurry image. Recently, there has been a significant effort on understanding the basic mechanisms to solve blind deconvolution. While this effort…

Computer Vision and Pattern Recognition · Computer Science 2014-12-02 Daniele Perrone , Paolo Favaro

Archetypal scenarios for change detection generally consider two images acquired through sensors of the same modality. However, in some specific cases such as emergency situations, the only images available may be those acquired through…

Computer Vision and Pattern Recognition · Computer Science 2016-09-21 Vinicius Ferraris , Nicolas Dobigeon , Qi Wei , Marie Chabert

Low-frequency radio observatories are reaching unprecedented levels of sensitivity in an effort to detect the 21 cm signal from the Cosmic Dawn. High precision is needed because the expected signal is overwhelmed by foreground…

Instrumentation and Methods for Astrophysics · Physics 2022-03-14 Adam E. Lanman , Steven G. Murray , Daniel C. Jacobs
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