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Imaging in radio astronomy is usually carried out with a single-dish radio telescope doing a raster scan of a region of the sky or with an interferometer that samples the visibility function of the sky brightness. Mosaic observations are…

Instrumentation and Methods for Astrophysics · Physics 2019-06-12 Urvashi Rau , Nikhil Naik , Timothy Braun

The distribution of cosmological neutral hydrogen will provide a new window into the large-scale structure of the Universe with the next generation of radio telescopes and surveys. The observation of this material, through 21cm line…

Cosmology and Nongalactic Astrophysics · Physics 2020-08-28 Jacobo Asorey , David Parkinson , Feng Shi , Yong-Seon Song , Kyungjin Ahn , Juhan Kim , Jian Yao , Le Zhang , Shifan Zuo

Light field deconvolution allows three-dimensional investigations from a single snapshot recording of a plenoptic camera. It is based on a linear image formation model, and iterative volume reconstruction requires to define the…

Image and Video Processing · Electrical Eng. & Systems 2021-07-28 Martin Eberhart

An important application of next-generation wide-field radio interferometers is making high dynamic range maps of radio emission. Traditional deconvolution methods like CLEAN can give poor recovery of diffuse structure, prompting the…

Instrumentation and Methods for Astrophysics · Physics 2024-10-23 Katrine A. Glasscock , Philip Bull , Jacob Burba , Hugh Garsden , Michael J. Wilensky

Observations of redshifted 21cm radiation from HI at high redshifts is an important future probe of reionization. We consider the Multi-frequency Angular Power Spectrum (MAPS) to quantify the statistics of the HI signal as a joint function…

Astrophysics · Physics 2008-11-26 Kanan K. Datta , T. Roy Choudhury , Somnath Bharadwaj

For submillimeter spectroscopy with ground-based single-dish telescopes, removing noise contribution from the Earth's atmosphere and the instrument is essential. For this purpose, here we propose a new method based on a data-scientific…

Instrumentation and Methods for Astrophysics · Physics 2021-08-20 Akio Taniguchi , Yoichi Tamura , Shiro Ikeda , Tatsuya Takekoshi , Ryohei Kawabe

We argue that the decomposition of gamma-ray maps in spherical harmonics is a sensitive tool to study dark matter (DM) annihilation or decay in the main Galactic halo of the Milky Way. Using the spherical harmonic decomposition in a window…

High Energy Astrophysical Phenomena · Physics 2011-08-12 Dmitry Malyshev , Jo Bovy , Ilias Cholis

While most purpose-built 21cm intensity mapping experiments are close-packed interferometer arrays, general-purpose dish arrays should also be capable of measuring the cosmological 21cm signal. This can be achieved most efficiently if the…

The fundamental mechanism driving MIMO beamforming is the relative phases of signals departing the transmit array and arriving at the receive array. If a propagation channel affects all transmitted signals equally, the relative phases are a…

Signal Processing · Electrical Eng. & Systems 2026-01-21 Oliver Kirkpatrick , Santiago Ozafrain , Christopher Gilliam , Beth Jelfs

Acquiring precise information about the mode content of a laser is critical for multiplexed optical communications, optical imaging with active wave-front control, and quantum-limited interferometric measurements. Hologram-based mode…

We present a method for extracting the expected cosmological 21-cm signal from the epoch of reionization, taking into account contaminating radiations and random instrumental noise. The method is based on the maximum a-posteriori…

Astrophysics · Physics 2008-12-21 Liron Gleser , Adi Nusser , Andrew J. Benson

In radio astronomy, the challenge of reconstructing a sky map from time ordered data (TOD) is known as an inverse problem. Standard map-making techniques and gridding algorithms are commonly employed to address this problem, each offering…

Instrumentation and Methods for Astrophysics · Physics 2023-06-28 Haolin Zhang , Shifan Zuo , Le Zhang

Spherical harmonics (SH) have been extensively used as a basis for analyzing the morphology of particles in granular mechanics. The use of SH is facilitated by mapping the particle coordinates onto a unit sphere, in practice often a…

Soft Condensed Matter · Physics 2024-11-14 Mahmoud Shaqfa , Wim M. van Rees

Despite being designed as an interferometer, the MeerKAT radio array (an SKA pathfinder) can also be used in autocorrelation (`single-dish') mode, where each dish scans the sky independently. Operating in this mode allows extremely high…

Cosmology and Nongalactic Astrophysics · Physics 2021-07-14 Fraser Kennedy , Philip Bull

We develop a general framework for quantifying the many different contributions to the noise budget of an image made with an array of dishes or aperture array stations. Each noise contribution to the visibility data is associated with a…

Instrumentation and Methods for Astrophysics · Physics 2015-06-11 Robert Braun

Characterizing sound field diffuseness has many practical applications, from room acoustics analysis to speech enhancement and sound field reproduction. In this paper we investigate how spherical microphone arrays (SMAs) can be used to…

Sound · Computer Science 2016-07-04 Nicolas Epain , Craig T. Jin

The method of time delay interferometry (TDI) is proposed to cancel the laser noise in space-borne gravitational-wave detectors. Among all different TDI combinations, the most commonly used ones are the orthogonal channels A, E and T, where…

Astrophysics of Galaxies · Physics 2023-08-09 Zheng-Cheng Liang , Zhi-Yuan Li , Jun Cheng , En-Kun Li , Jian-dong Zhang , Yi-Ming Hu

Using a combination of N-body simulations, semi-analytic models and radiative transfer calculations, we have estimated the theoretical cross power spectrum between galaxies and the 21cm emission from neutral hydrogen during the epoch of…

We re-examine the effects of redshift space distortion in all-sky galaxy redshift surveys in the formalism of spherical harmonics. Within this framework we show how one can treat both the large-scale linear effects, and the small-scale…

Astrophysics · Physics 2015-06-24 A. F. Heavens , A. N. Taylor

The ambitious scientific goals of the SKA require a matching capability for calibration of atmospheric propagation errors, which contaminate the observed signals. We demonstrate a scheme for correcting the direction-dependent ionospheric…

Instrumentation and Methods for Astrophysics · Physics 2018-07-18 Maria Rioja , Richard Dodson , Thomas Franzen