Publications related to Very-long-baseline interferometry

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

Periodic and aperiodic NiFe nanomagnet/ferrimagnet hybrid structures for 2D magnon steering and interferometry with high extinction ratio

Dirk Grundler, Sho Watanabe, Andrea Mucchietto, Shixuan Shan, Elif Nur Dayi, Vinayak Shantaram Bhat

File formats are described in read_me files in the concerning folder. For plotting and data evaluation, Python 2.7 was used. Example scripts for plotting are provided. ...

Zenodo2023

Photonic radar for contactless vital sign detection

Yang Liu

Vital sign detection is used across ubiquitous scenarios in medical and health settings, and contact and wearable sensors have been widely deployed. However, they are unsuitable for patients with burn wounds or infants with insufficient areas for attachmen ...

Nature Publishing Group2023

Periodic and Aperiodic NiFe Nanomagnet/Ferrimagnet Hybrid Structures for 2D Magnon Steering and Interferometry with High Extinction Ratio

Dirk Grundler, Sho Watanabe, Andrea Mucchietto, Shixuan Shan, Elif Nur Dayi, Vinayak Shantaram Bhat

Magnons, quanta of spin waves, are known to enable information processing with low power consumption at the nanoscale. So far, however, experimentally realized half-adders, wave-logic and binary output operations were based on few µm-long spin waves and re ...

Wiley2023

Towards More Accurate Radio Telescope Images

Paul Hurley, Matthieu Martin Jean-André Simeoni, Nezihe Merve Gürel

Radio interferometry usually compensates for high levels of noise in sensor/antenna electronics by throwing data and energy at the problem: observe longer, then store and process it all. We propose instead a method to remove the noise explicitly before ima ...

IEEE2018

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

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

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

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

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

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

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

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, Rafael Eduardo Carrillo Rangel, Jason Douglas McEwen

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

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

Detailed Heat Transfer Distributions of Narrow Impingement Channels with Varying Jet Diameter

Peter Ott, Alexandros Terzis, Bernhard Weigand

The development of integrally cast turbine airfoils allows the production of narrow impingement channels in a double-wall configuration, where the coolant is practically injected within the wall of the airfoil providing increased heat transfer capabilities ...

ASME2014

The varying w spread spectrum effect for radio interferometric imaging

Yves Wiaux, Rafael Eduardo Carrillo Rangel, Jason Douglas McEwen

We study the impact of the spread spectrum effect in radio interferometry on the quality of image reconstruction. This spread spectrum effect will be induced by the wide ﬁeld-of-view of forthcoming radio interferometric telescopes. The resulting chirp modu ...

2013

Sparsity Averaging Reweighted Analysis (SARA): a novel algorithm for radio-interferometric imaging

Yves Wiaux, Rafael Eduardo Carrillo Rangel, Jason Douglas McEwen

We propose a novel algorithm for image reconstruction in radio interferometry. The ill-posed inverse problem associated with the incomplete Fourier sampling identified by the visibility measurements is regularized by the assumption of average signal sparsi ...

OUP2012

About the performance of multi-dimensional radial self-navigation incorporating compressed sensing for free-breathing coronary MRI

Yves Wiaux, Gilles Puy, Ruud van Heeswijk, Gabriele Vincenzo Bonanno

Respiratory motion is a major challenge in cardiac magnetic resonance imaging (MRI) and contemporary state-of-the-art motion compensation strategies like diaphragmatic navigators still suffer from sub-optimal time efficiency. In response, k-space- based on ...

2012

Compressed sensing for radio interferometric imaging: review and future

Yves Wiaux, Jason Douglas McEwen

Radio interferometry is a powerful technique for astronomical imaging. The theory of compressed sensing (CS) has been applied recently to the ill-posed inverse problem of recovering images from the measurements taken by radio interferometric telescopes. We ...

Ieee Service Center, 445 Hoes Lane, Po Box 1331, Piscataway, Nj 08855-1331 Usa2011

COSMOGRAIL: the COSmological MOnitoring of GRAvItational Lenses

Frédéric Courbin, Georges Meylan, Yves Revaz, Malte Tewes

We present accurate time delays for the quadruply imaged quasar HE 0435-1223. The delays were measured from 575 independent photometric points obtained in the R-band between January 2004 and March 2010. With seven years of data, we clearly show that quasar ...

2011

Spread spectrum for interferometric and magnetic resonance imaging

Jean-Philippe Thiran, Rolf Gruetter, Pierre Vandergheynst, Dimitri Nestor Alice Van De Ville, Yves Wiaux, Gilles Puy

We consider images probed through incomplete and noisy Fourier coverages, both in the context of radio interferometry (RI) and of magnetic resonance imaging (MRI). We show that the quality of signal reconstruction can be signiﬁcantly enhanced by the introd ...

IEEE Signal Process. Soc.2010

Compressed sensing reconstruction of a string signal from interferometric observations of the cosmic microwave background

Pierre Vandergheynst, Yves Wiaux, Gilles Puy

We propose an algorithm for the reconstruction of the signal induced by cosmic strings in the cosmic microwave background (CMB), from radio-interferometric data at arcminute resolution. Radio interferometry provides incomplete and noisy Fourier measurement ...

Wiley-Blackwell2010