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Radio interferometry calibration and Radio Frequency Interference (RFI) removal are usually done separately. Here we show that jointly modelling the antenna gains and RFI has significant benefits when the RFI follows precise trajectories,…

Instrumentation and Methods for Astrophysics · Physics 2025-02-19 Chris Finlay , Bruce A. Bassett , Martin Kunz , Nadeem Oozeer

In order to cope with the increased data volumes generated by modern radio interferometers such as LOFAR (Low Frequency Array) or SKA (Square Kilometre Array), fast and efficient calibration algorithms are essential. Traditional radio…

Instrumentation and Methods for Astrophysics · Physics 2016-11-15 Sarod Yatawatta

We recently proposed the use of consensus optimization as a viable and effective way to improve the quality of calibration of radio interferometric data. We showed that it is possible to obtain far more accurate calibration solutions and…

Instrumentation and Methods for Astrophysics · Physics 2016-05-31 Sarod Yatawatta

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

We propose an eigenvector-based formalism for the calibration of radio interferometer arrays. In the presence of a strong dominant point source, the complex gains of the array can be obtained by taking the first eigenvector of the…

Instrumentation and Methods for Astrophysics · Physics 2019-06-14 Shifan Zuo , Ue-Li Pen , Fengquan Wu , Jixia Li , Albert Stebbins , Yougang Wang , Xuelei Chen

We present a simple and efficient Bayesian recursive algorithm for the data-pattern scheme for quantum state reconstruction, which is applicable to situations where measurement settings can be controllably varied efficiently. The algorithm…

In practice, the finite number of samples of the spherical radiation pattern or antenna gain are taken on the sphere for both the reconstruction of the antenna radiation pattern and the computation of mobile handset performance measures…

Signal Processing · Electrical Eng. & Systems 2018-12-03 Umair Ahmed , Zubair Khalid

Photometric surveys have provided incredible amounts of astronomical information in the form of images. However, astronomical images often contain artifacts that can critically hinder scientific analysis by misrepresenting intensities or…

Instrumentation and Methods for Astrophysics · Physics 2020-06-03 Suchetha Cooray , Tsutomu T. Takeuchi , Moe Yoda , Kazuo Sorai

One of the aims of next generation optical interferometric instrumentation is to be able to make use of information contained in the visibility phase to construct high dynamic range images. Radio and optical interferometry are at the two…

One of the biggest challenges in operating massive multiple-input multiple-output systems is the acquisition of accurate channel state information at the transmitter. To take up this challenge, time division duplex is more favorable thanks…

Information Theory · Computer Science 2024-10-30 Xiwen Jiang , Alexis Decurninge , Kalyana Gopala , Florian Kaltenberger , Maxime Guillaud , Dirk Slock , Luc Deneire

Uncertainty quantification is a critical missing component in radio interferometric imaging that will only become increasingly important as the big-data era of radio interferometry emerges. Since radio interferometric imaging requires…

Instrumentation and Methods for Astrophysics · Physics 2018-09-12 Xiaohao Cai , Marcelo Pereyra , Jason D. McEwen

We developed a radio interferometric technique for the observation of extensive air showers initiated by cosmic particles. In this proof-of-principle study we show that properties of extensive air showers can be derived with high accuracy…

High Energy Astrophysical Phenomena · Physics 2022-01-11 Harm Schoorlemmer , Washington R. Carvalho

A new generation of wide-field radio interferometers designed for 21-cm surveys is being built as drift scan instruments allowing them to observe large fractions of the sky. With large numbers of antennas and frequency channels the enormous…

Instrumentation and Methods for Astrophysics · Physics 2017-10-10 Philippe Berger , Niels Oppermann , Ue-Li Pen , J. Richard Shaw

Gain calibration of x-ray area detectors is a challenge due to the inability to generate an x-ray flat field at the selected photon energy that the beamline operates at, which has a strong influence on the detector's gain behavior. A method…

We explore a new Bayesian method of detecting galaxies from radio interferometric data of the faint sky. Working in the Fourier domain, we fit a single, parameterised galaxy model to simulated visibility data of star-forming galaxies. The…

Instrumentation and Methods for Astrophysics · Physics 2019-04-17 Adam Malyali , Marzia Rivi , Filipe B. Abdalla , Jason D. McEwen

This study investigates some of the consequences of representing the sky by a rectangular grid of pixels on the dynamic range of images derived from radio interferometric measurements. In particular, the effects of image pixelization…

Astrophysics · Physics 2009-11-13 W. D. Cotton , Juan M. Uson

Bayesian imaging inverse problems in astrophysics and cosmology remain challenging, particularly in low-data regimes, due to complex forward operators and the frequent lack of well-motivated priors for non-Gaussian signals. In this paper,…

Instrumentation and Methods for Astrophysics · Physics 2026-02-06 Sébastien Pierre , Erwan Allys , Pablo Richard , Roman Soletskyi , Alexandros Tsouros

Observation of multifrequency angular power spectrum of the redshifted 21-cm brightness temperature fluctuation from the neutral hydrogen holds the key to understand the structure formation and its evolution during the reionization and…

Cosmology and Nongalactic Astrophysics · Physics 2025-05-28 Saikat Gayen , Jais Kumar , Prasun Dutta , Khandakar Md Asif Elahi , Samir Choudhuri , Nirupam Roy

Measurement of the global 21-cm signal during Cosmic Dawn (CD) and the Epoch of Reionization (EoR) is made difficult by bright foreground emission which is 2-5 orders of magnitude larger than the expected signal. Fitting for a…

Cosmology and Nongalactic Astrophysics · Physics 2024-02-20 Michael Pagano , Peter Sims , Adrian Liu , Dominic Anstey , Will Handley , Eloy De Lera Acedo

We propose a coherent method for the detection and reconstruction of gravitational wave signals for a network of interferometric detectors. The method is derived using the likelihood functional for unknown signal waveforms. In the standard…

General Relativity and Quantum Cosmology · Physics 2008-11-26 S. Klimenko , S. Mohanty , M. Rakhmanov , G. Mitselmakher , .