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Radio interferometers are phased arrays producing high-resolution images from the covariance matrix of measurements. Calibration of such instruments is necessary and is a critical task. This is how the estimation of instrumental errors is…

Instrumentation and Methods for Astrophysics · Physics 2023-09-26 Yassine Mhiri , Mohammed Nabil El Korso , Arnaud Breloy , Pascal Larzabal

The estimation of phase errors from digital-holography data is critical for applications such as imaging or wave-front sensing. Conventional techniques require multiple i.i.d. data and perform poorly in the presence of high noise or large…

Data Analysis, Statistics and Probability · Physics 2017-10-11 Casey J. Pellizzari , Mark F. Spencer , Charles A. Bouman

This paper investigates the possibility of improving radio interferometric images using an algorithm inspired by an optical method known as "lucky imaging", which would give more weight to the best-calibrated visibilities used to make a…

Instrumentation and Methods for Astrophysics · Physics 2018-07-18 Etienne Bonnassieux , Cyril Tasse , Oleg Smirnov , Philippe Zarka

We present a novel machine learning based approach for detecting galaxy-scale gravitational lenses from interferometric data, specifically those taken with the International LOFAR Telescope (ILT), which is observing the northern radio sky…

Astrophysics of Galaxies · Physics 2022-08-03 S. Rezaei , J. P. McKean , M. Biehl , W. de Roo1 , A. Lafontaine

The ambitious scientific goals of SKA require a matching capability for calibration of instrumental and atmospheric propagation contributions as functions of time, frequency and position. The development of novel calibration algorithms to…

Instrumentation and Methods for Astrophysics · Physics 2022-02-01 María J. Rioja , Richard Dodson

The Earth's ionosphere refracts radio waves incident on an interferometer, resulting in shifts to the measured positions of radio sources. We present a method to smoothly remove these shifts and restore sources to their reference positions,…

Instrumentation and Methods for Astrophysics · Physics 2018-08-27 N. Hurley-Walker , P. J. Hancock

Accurately calibrating light field camera is essential to its applications. Rapid progress has been made in this area in the past decades. In this paper, detailed analysis was first performed towards the state of the art projection models…

Computer Vision and Pattern Recognition · Computer Science 2021-03-11 Dongyang Jin , Saiping Zhang , Xiao Huo , Wei Zhang , Fuzheng Yang

The 21-cm signal of neutral hydrogen - emitted during the Epoch of Reionization - promises to be an important source of information for the study of the infant universe. However, its detection is impossible without sufficient mitigation of…

Instrumentation and Methods for Astrophysics · Physics 2019-01-09 A. Mouri Sardarabadi , L. V. E. Koopmans

The Naval Research Laboratory and the National Radio Astronomy Observatory completed implementation of a low frequency capability on the VLA at 73.8 MHz in 1998. This frequency band offers unprecedented sensitivity (~25 mJy/beam) and…

We study the impact of sky-based calibration errors from source mismodeling on 21\,cm power spectrum measurements with an interferometer and propose a method for suppressing their effects. While emission from faint sources that are not…

Cosmology and Nongalactic Astrophysics · Physics 2017-07-26 Aaron Ewall-Wice , Joshua S. Dillon , Adrian Liu , Jacqueline Hewitt

Fourier ptychography captures intensity images with varying source patterns (illumination angles) in order to computationally reconstruct large space-bandwidth-product images. Accurate knowledge of the illumination angles is necessary for…

Signal Processing · Electrical Eng. & Systems 2018-11-01 Regina Eckert , Zachary F. Phillips , Laura Waller

Holographic microscopy combined with forward modeling and inference allows colloidal particles to be characterized and tracked in three dimensions with high precision. However, current models ignore the effects of optical aberrations on…

Optics · Physics 2021-05-27 Caroline Martin , Brian Leahy , Vinothan Manoharan

Phase referencing is a standard calibration procedure in radio interferometry. It allows to detect weak sources by using quasi-simultaneous observations of closeby sources acting as calibrators. Therefore, it is assumed that, for each…

Instrumentation and Methods for Astrophysics · Physics 2011-01-25 I. Marti-Vidal , J. C. Guirado , S. Jimenez-Monferrer , J. M. Marcaide

Intrinsic alignments (IAs) of galaxies are an important contaminant for cosmic shear studies, but the modelling is complicated by the dependence of the signal on the source galaxy sample. In this paper, we use the halo model formalism to…

Cosmology and Nongalactic Astrophysics · Physics 2020-12-16 Maria Cristina Fortuna , Henk Hoekstra , Benjamin Joachimi , Harry Johnston , Nora Elisa Chisari , Christos Georgiou , Constance Mahony

Phase diffusion represents a crucial obstacle towards the implementation of high precision interferometric measurements and phase shift based communication channels. Here we present a nearly optimal interferometric scheme based on homodyne…

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 aimed high sensitivities and large fields of view of the new generation of interferometers impose to reach high dynamic range of order $\sim$1:$10^6$ to 1:$10^8$ in the case of the Square Kilometer Array. The main problem is the…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 C. Tasse , B. van der Tol , J. van Zwieten , Ger van Diepen , S. Bhatnagar

Calibrating out per-antenna signal chain effects is an essential step in analyzing radio interferometric data. For drift-scanning arrays, robustly calibrating the data is especially challenging due to the lack of the ability to track a…

Instrumentation and Methods for Astrophysics · Physics 2026-02-09 Robert Pascua , Jonathan Sievers , Adrian Liu

This paper describes the processing applied to the HFI cleaned time-ordered data to produce photometrically calibrated maps. HFI observes the sky over a broad range of frequencies, from 100 to 857 GHz. To get the best accuracy on the…

Cosmology and Nongalactic Astrophysics · Physics 2014-10-29 Planck Collaboration , P. A. R. Ade , N. Aghanim , C. Armitage-Caplan , M. Arnaud , M. Ashdown , F. Atrio-Barandela , J. Aumont , C. Baccigalupi , A. J. Banday , R. B. Barreiro , E. Battaner , K. Benabed , A. Benoît , A. Benoit-Lévy , J. -P. Bernard , M. Bersanelli , B. Bertincourt , P. Bielewicz , J. Bobin , J. J. Bock , J. R. Bond , J. Borrill , F. R. Bouchet , F. Boulanger , M. Bridges , M. Bucher , C. Burigana , J. -F. Cardoso , A. Catalano , A. Challinor , A. Chamballu , R. -R. Chary , X. Chen , L. -Y Chiang , H. C. Chiang , P. R. Christensen , S. Church , D. L. Clements , S. Colombi , L. P. L. Colombo , C. Combet , F. Couchot , A. Coulais , B. P. Crill , A. Curto , F. Cuttaia , L. Danese , R. D. Davies , P. de Bernardis , A. de Rosa , G. de Zotti , J. Delabrouille , J. -M. Delouis , F. -X. Désert , C. Dickinson , J. M. Diego , H. Dole , S. Donzelli , O. Doré , M. Douspis , X. Dupac , G. Efstathiou , T. A. Enßlin , H. K. Eriksen , C. Filliard , F. Finelli , O. Forni , M. Frailis , E. Franceschi , S. Galeotta , K. Ganga , M. Giard , G. Giardino , Y. Giraud-Héraud , J. González-Nuevo , K. M. Górski , S. Gratton , A. Gregorio , A. Gruppuso , F. K. Hansen , D. Hanson , D. Harrison , G. Helou , S. Henrot-Versillé , C. Hernández-Monteagudo , D. Herranz , S. R. Hildebrandt , E. Hivon , M. Hobson , W. A. Holmes , A. Hornstrup , W. Hovest , K. M. Huffenberger , T. R. Jaffe , A. H. Jaffe , W. C. Jones , M. Juvela , E. Keihänen , R. Keskitalo , T. S. Kisner , R. Kneissl , J. Knoche , L. Knox , M. Kunz , H. Kurki-Suonio , G. Lagache , J. -M. Lamarre , A. Lasenby , R. J. Laureijs , C. R. Lawrence , M. Le Jeune , E. Lellouch , R. Leonardi , C. Leroy , J. Lesgourgues , M. Liguori , P. B. Lilje , M. Linden-Vørnle , M. López-Caniego , P. M. Lubin , J. F. Macías-Pérez , B. Maffei , N. Mandolesi , M. Maris , D. J. Marshall , P. G. Martin , E. Martínez-González , S. Masi , S. Matarrese , F. Matthai , L. Maurin , P. Mazzotta , P. McGehee , P. R. Meinhold , A. Melchiorri , L. Mendes , A. Mennella , M. Migliaccio , S. Mitra , M. -A. Miville-Deschênes , A. Moneti , L. Montier , R. Moreno , G. Morgante , D. Mortlock , D. Munshi , J. A. Murphy , P. Naselsky , F. Nati , P. Natoli , C. B. Netterfield , H. U. Nørgaard-Nielsen , F. Noviello , D. Novikov , I. Novikov , S. Osborne , C. A. Oxborrow , F. Paci , L. Pagano , F. Pajot , R. Paladini , D. Paoletti , B. Partridge , F. Pasian , G. Patanchon , O. Perdereau , L. Perotto , F. Perrotta , F. Piacentini , M. Piat , E. Pierpaoli , D. Pietrobon , S. Plaszczynski , E. Pointecouteau , G. Polenta , N. Ponthieu , L. Popa , T. Poutanen , G. W. Pratt , G. Prézeau , S. Prunet , J. -L. Puget , J. P. Rachen , M. Reinecke , M. Remazeilles , C. Renault , S. Ricciardi , T. Riller , I. Ristorcelli , G. Rocha , C. Rosset , G. Roudier , B. Rusholme , D. Santos , G. Savini , E. P. S. Shellard , L. D. Spencer , J. -L. Starck , V. Stolyarov , R. Stompor , R. Sudiwala , R. Sunyaev , F. Sureau , D. Sutton , A. -S. Suur-Uski , J. -F. Sygnet , J. A. Tauber , D. Tavagnacco , S. Techene , L. Terenzi , M. Tomasi , M. Tristram , M. Tucci , G. Umana , L. Valenziano , J. Valiviita , B. Van Tent , P. Vielva , F. Villa , N. Vittorio , L. A. Wade , B. D. Wandelt , D. Yvon , A. Zacchei , A. Zonca

Quantitative inversion algorithms allow for the reconstruction of electrical properties (such as permittivity, and conductivity) for every point in a scene. However, they are challenging to use on measured datasets due to the need to know…

Signal Processing · Electrical Eng. & Systems 2025-05-15 Zacharie Idriss , Raghu Raj