English
Related papers

Related papers: Parametric high resolution techniques for radio as…

200 papers

Radio-astronomical observations are increasingly contaminated by interference, and suppression techniques become essential. A powerful candidate for interference mitigation is adaptive spatial filtering. We study the effect of spatial…

Astrophysics · Physics 2014-10-13 Amir Leshem , Alle-Jan van der Veen

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

The fidelity of radio astronomical images is generally assessed by practical experience, i.e. using rules of thumb, although some aspects and cases have been treated rigorously. In this paper we present a mathematical framework capable of…

Instrumentation and Methods for Astrophysics · Physics 2010-03-12 Stefan J. Wijnholds , Alle-Jan van der Veen

Next generation radio telescopes will be much larger, more sensitive, have much larger observation bandwidth and will be capable of pointing multiple beams simultaneously. Obtaining the sensitivity, resolution and dynamic range supported by…

Instrumentation and Methods for Astrophysics · Physics 2010-09-03 Ronny Levanda , Amir Leshem

We introduce a loss compensation method to increase the resolution of near-field imaging with a plasmonic superlens that relies on the convolution of a high spatial frequency passband function with the object. Implementation with incoherent…

Optics · Physics 2018-01-23 Wyatt Adams , Anindya Ghoshroy , Durdu Ö. Güney

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

We consider the problem of mapping with ultra-high angular resolution using a space-ground radio interferometer with a space antenna in a high orbit,whose apogee height exceeds the radius of the Earth by a factor of ten. In this case, a…

Astrophysics · Physics 2009-11-13 Anisa T. Bajkova

The paper reviews progress in imaging in radio interferometry for the period 1993-1996. Unlike an optical telescope, the basic measurements of a radio interferometer (correlations between antennas) are indirectly related to a sky brightness…

Astrophysics · Physics 2007-05-23 R. J. Sault , T. A. Oosterloo

Imaging in thick biological tissues is often degraded by sample-induced aberrations, which reduce image quality and resolution, particularly in super-resolution techniques. While hardware-based adaptive optics, which correct aberrations…

Radio interferometry enables high-resolution imaging of astronomical radio sources by synthesizing a large effective aperture from an array of antennas and solving a deconvolution problem to reconstruct the image. Deep learning has emerged…

Instrumentation and Methods for Astrophysics · Physics 2026-03-11 Zihui Wu , Liam Connor , Samuel McCarty , Katherine L. Bouman

In order to meet the theoretically achievable imaging performance, calibration of modern radio interferometers is a mandatory challenge, especially at low frequencies. In this perspective, we propose a novel parallel iterative…

Instrumentation and Methods for Astrophysics · Physics 2016-09-09 Martin Brossard , Mohammed Nabil El Korso , Marius Pesavento , Rémy Boyer , Pascal Larzabal , Stefan J. Wijnholds

Most image deblurring methods assume an over-simplistic image formation model and as a result are sensitive to more realistic image degradations. We propose a novel variational framework, that explicitly handles pixel saturation, noise,…

Computer Vision and Pattern Recognition · Computer Science 2018-06-05 Jérémy Anger , Mauricio Delbracio , Gabriele Facciolo

In recent works, sparse models and convex optimization techniques have been applied to radio-interferometric (RI) imaging showing the potential to outperform state-of-the-art imaging algorithms in the field. In this talk, I will review our…

Instrumentation and Methods for Astrophysics · Physics 2015-02-19 Rafael E. Carrillo , Jason D. McEwen , Yves Wiaux

Here we present a new non-parametric approach to density estimation and classification derived from theory in Radon transforms and image reconstruction. We start by constructing a "forward problem" in which the unknown density is mapped to…

Numerical Analysis · Mathematics 2024-12-20 James Webber , Erika Hussey , Eric Miller , Shuchin Aeron

Designing unimodular waveforms with a desired beampattern, spectral occupancy and orthogonality level is of vital importance in the next generation Multiple-Input Multiple-Output (MIMO) radar systems. Motivated by this fact, in this paper,…

Signal Processing · Electrical Eng. & Systems 2021-12-14 Ehsan Raei , Saeid Sedighi , Mohammad Alaee-Kerahroodi , M. R. Bhavani Shankar

The interest of compressive sampling in ultrasound imaging has been recently extensively evaluated by several research teams. Following the different application setups, it has been shown that the RF data may be reconstructed from a small…

Computer Vision and Pattern Recognition · Computer Science 2015-12-07 Zhouye Chen , Adrian Basarab , Denis Kouamé

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

Hyperspectral imaging is a cutting-edge type of remote sensing used for mapping vegetation properties, rock minerals and other materials. A major drawback of hyperspectral imaging devices is their intrinsic low spatial resolution. In this…

Computer Vision and Pattern Recognition · Computer Science 2022-08-16 Leon Bungert , David A. Coomes , Matthias J. Ehrhardt , Jennifer Rasch , Rafael Reisenhofer , Carola-Bibiane Schönlieb

In the past years modern mathematical methods for image analysis have led to a revolution in many fields, from computer vision to scientific imaging. However, some recently developed image processing techniques successfully exploited by…

Instrumentation and Methods for Astrophysics · Physics 2015-01-19 Marco Castellano , Daniele Ottaviani , Adriano Fontana , Emiliano Merlin , Stefano Pilo , Maurizio Falcone
‹ Prev 1 2 3 10 Next ›