Publications related to Towards More Accurate Radio Telescope Images

Quantum radio astronomy: Data encodings and quantum image processing

Jean-Paul Richard Kneib, Emma Elizabeth Tolley, Stefano Corda

We explore applications of quantum computing for radio interferometry and astronomy using recent developments in quantum image processing. We evaluate the suitability of different quantum image representations using a toy quantum computing image reconstruc ...

Elsevier2024

Hydrogen Intensity and Real-Time Analysis Experiment: 256-element array status and overview

Jean-Paul Richard Kneib, Martin Kunz, Emma Elizabeth Tolley, Zeyu Zhang, Carolyn Marie Crichton

The Hydrogen Intensity and Real-time Analysis Experiment (HIRAX) is a radio interferometer array currently in development, with an initial 256-element array to be deployed at the South African Radio Astronomy Observatory Square Kilometer Array site in Sout ...

SPIE-SOC PHOTO-OPTICAL INSTRUMENTATION ENGINEERS2022

Development and evaluation of galaxy shape measurement algorithms for radio interferometric data

Vasileios Angelopoulos

The purpose of this Thesis is to develop, test, and characterize different models attempting to tackle the problem of measurement of galaxy shapes applied in interferometric observations. Shape measurement is a tool for estimating the underlying shear due ...

EPFL2021

The e-MERGE Survey (e-MERLIN Galaxy Evolution Survey): overview and survey description

Jean-Paul Richard Kneib, Cole Stewart Simpson, Mark Thomas Sargent

We present an overview and description of the e-MERGE Survey (e-MERLIN Galaxy Evolution Survey) Data Release 1 (DR1), a large program of high-resolution 1.5-GHz radio observations of the GOODS-N field comprising similar to 140 h of observations with enhanc ...

OXFORD UNIV PRESS2020

Multiwavelength cross-correlation analysis of the simulated cosmic web

Claudio Gheller

We used magnetohydrodynamical cosmological simulations to investigate the cross-correlation between different observables (i.e. X-ray emission, Sunyaev-Zeldovich (SZ) signal at 21 cm, HI temperature decrement, diffuse synchrotron emission, and Faraday Rota ...

2020

Ultralow-noise photonic microwave synthesis using a soliton microcomb-based transfer oscillator

Tobias Kippenberg, Erwan Guillaume Albert Lucas

The synthesis of ultralow-noise microwaves is of both scientific and technological relevance for timing, metrology, communications and radio-astronomy. Today, the lowest reported phase noise signals are obtained via optical frequency-division using mode-lo ...

Nature Publishing Group2020

A radio ridge connecting two galaxy clusters in a filament of the cosmic web

Claudio Gheller

Galaxy clusters are the most massive gravitationally bound structures in the Universe. They grow by accreting smaller structures in a merging process that produces shocks and turbulence in the intracluster gas. We observed a ridge of radio emission connect ...

American Association for the Advancement of Science2019

Feedback-Aware Precoding for Millimeter Wave Massive MIMO Systems

Andreas Peter Burg, Reza Ghanaatian Jahromi

Millimeter wave (mmWave) communication is a promising solution for coping with the ever-increasing mobile data traffic because of its large bandwidth. To enable a sufficient link margin, a large antenna array employing directional beamforming, which is ena ...

IEEE2019

Graph Spectral Clustering of Convolution Artefacts in Radio Interferometric Images

Paul Hurley, Matthieu Martin Jean-André Simeoni

The starting point for deconvolution methods in radioastronomy is an estimate of the sky intensity called a dirty image. These methods rely on the telescope point-spread function so as to remove artefacts which pollute it. In this work, we show that the in ...

IEEE2019

Low-dimensional data embedding for scalable astronomical imaging in the SKA telescope era

Vijay Kartik

Astronomy is one of the oldest sciences known to humanity. We have been studying celestial objects for millennia, and continue to peer deeper into space in our thirst for knowledge about our origins and the universe that surrounds us. Radio astronomy -- ob ...

EPFL2018

Looking beyond Pixels : Theory, Algorithms and Applications of Continuous Sparse Recovery

Hanjie Pan

Sparse recovery is a powerful tool that plays a central role in many applications, including source estimation in radio astronomy, direction of arrival estimation in acoustics or radar, super-resolution microscopy, and X-ray crystallography. Conventional a ...

EPFL2018

LEAP: Looking beyond pixels with continuous-space EstimAtion of Point sources

Martin Vetterli, Paul Hurley, Thierry Blu, Hanjie Pan, Matthieu Martin Jean-André Simeoni

Context. Two main classes of imaging algorithms have emerged in radio interferometry: the CLEAN algorithm and its multiple variants, and compressed-sensing inspired methods. They are both discrete in nature, and estimate source locations and intensities on ...

2017

A Fourier dimensionality reduction model for big data interferometric imaging

Jean-Philippe Thiran, Yves Wiaux, Rafael Eduardo Carrillo Rangel, Vijay Kartik

Data dimensionality reduction in radio interferometry can provide savings of computational resources for image reconstruction through reduced memory footprints and lighter computations per iteration, which is important for the scalability of imaging method ...

Oxford Univ Press2017

Imaging in radio interferometry by iterative subset scanning using a modified amp algorithm

Paul Hurley, Sanaz Kazemi, Matthieu Martin Jean-André Simeoni, Giovanni Cherubini

Imaging techniques in radio interferometry often face a significant challenge posed by the large number of antenna signals received, from which the image information needs to be extracted. Beam- forming is envisaged to reduce the rate required for transpor ...

2016

Robust sparse image reconstruction of radio interferometric observations with PURIFY

Yves Wiaux, Jason Douglas McEwen, Rafael Eduardo Carrillo Rangel

Next-generation radio interferometers, such as the Square Kilometre Array (SKA), will revolutionise our understanding of the universe through their unprecedented sensitivity and resolution. However, to realise these goals significant challenges in image an ...

OUP2016

Direct Temperature Map Estimation in Optical Long Baseline Interferometry

Alessio Ferrari, Ferréol Arnaud Marie Soulez

We present a method to recontruct temperature map directly from spectro-interferometric data. It uses a sparse coding method to describe each pixel as a blackbody. Results are shown on the Herbig Be HD98922. Aside from recovering the mean environment tempe ...

SPIE2016

A randomised primal-dual algorithm for distributed radio-interferometric imaging

Yves Wiaux, Jason Douglas McEwen, Rafael Eduardo Carrillo Rangel

Next generation radio telescopes, like the Square Kilometre Array, will acquire an unprecedented amount of data for radio astronomy. The development of fast, parallelisable or distributed algorithms for handling such large-scale data sets is of prime impor ...

Ieee2016

Dimension embedding for big data in radio interferometry

Yves Wiaux, Rafael Eduardo Carrillo Rangel, Vijay Kartik

As radio telescope data is now increasingly high-dimensional, data reduction has become essential to reduce computational load while preserving accurate signal reconstruction. Gridding the continuous Fourier visibilities represents the standard approach to ...

2015

Reconfigurable Antennas for Beam-Space MIMO Transmission with a Single Radio

Mohsen Yousefbeiki

MIMO techniques allow remarkable improvements in the reliability and/or transmission rate of wireless communication systems. However, there are several major challenges towards the implementation of conventional MIMO concept in terminals with size, cost, a ...

EPFL2015

ARE ULTRA-FAINT GALAXIES AT z=6-8 RESPONSIBLE FOR COSMIC REIONIZATION? COMBINED CONSTRAINTS FROM THE HUBBLE FRONTIER FIELDS CLUSTERS AND PARALLELS

Johan Richard, Jean-Paul Richard Kneib, Hakim Atek, Mathilde Jauzac, Benjamin Yvan Alexandre Clement

We use deep Hubble Space Telescope imaging of the Frontier Fields to accurately measure the galaxy rest-frame ultraviolet luminosity function (UV LF) in the redshift range z similar to 6-8. We combine observations in three lensing clusters, A2744, MACS 041 ...

Iop Publishing Ltd2015