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Related papers: Estimating statistics of sky brightness using radi…

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We consider cosmological applications of galaxy number density correlations to be inferred from future deep and wide multi-band optical surveys. We mostly focus on very large scales as a probe of possible features in the primordial power…

Astrophysics · Physics 2009-11-13 Hu Zhan , Lloyd Knox , J. Anthony Tyson , Vera Margoniner

We consider the probe of astrophysical signals through radio interferometers with small field of view and baselines with non-negligible and constant component in the pointing direction. In this context, the visibilities measured essentially…

Instrumentation and Methods for Astrophysics · Physics 2009-11-16 Y. Wiaux , G. Puy , Y. Boursier , P. Vandergheynst

We present a method to map the artificial sky brightness across large territories in astronomical photometric bands with a resolution of approximately 1 km. This is useful to quantify the situation of night sky pollution, to recognize…

Astrophysics · Physics 2009-10-31 P. Cinzano , F. Falchi , C. D. Elvidge , K. E. Baugh

An extension may be proposed to the intensity interferometer of Hanbury Brown and Twiss to provide the Fourier phase measurement by the use of third-order intensity correlations. It is well known that interferometric reconstruction of…

Astrophysics · Physics 2008-06-14 B. E. Zhilyaev

Redshifted 21 cm radiation originating from the cosmological distribution of neutral hydrogen (HI) appears as a background radiation in low frequency radio observations. The angular and frequency domain fluctuations in this radiation carry…

Astrophysics · Physics 2007-05-23 Somnath Bharadwaj , SK. Saiyad Ali

Ground-based whole sky cameras are extensively used for localized monitoring of clouds nowadays. They capture hemispherical images of the sky at regular intervals using a fisheye lens. In this paper, we propose a framework for estimating…

Image and Video Processing · Electrical Eng. & Systems 2019-10-14 Soumyabrata Dev , Florian M. Savoy , Yee Hui Lee , Stefan Winkler

Angular anisotropy techniques for cosmic diffuse radiation maps are powerful probes, even for quite small data sets. A popular observable is the angular power spectrum; we present a detailed study applicable to any unbinned source skymap…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-23 Sheldon S. Campbell

We perform two distinct spatio-spectral reconstructions of the gamma-ray sky in the range of 0.56-316 GeV based on Fermi Large Area Telescope (LAT) data. Both describe the sky brightness to be composed of a diffuse-emission and a…

High Energy Astrophysical Phenomena · Physics 2023-12-13 Lukas I. Platz , Jakob Knollmüller , Philipp Arras , Philipp Frank , Martin Reinecke , Dominik Jüstel , Torsten A. Enßlin

The contribution of the Unresolved Extragalactic Radio Sources to the diffuse brightness of the sky was evaluated using the source number - flux measurements available in literature. We first optimized the fitting function of the data based…

Astrophysics · Physics 2009-11-13 M. Gervasi , A. Tartari , M. Zannoni , G. Boella , G. Sironi

Microwave, submillimetre-wave, and far-infrared phased arrays are of considerable importance for astronomy. We consider the behaviour imaging phased arrays and interferometric phased arrays from a functional perspective. It is shown that…

Astrophysics · Physics 2009-11-11 Stafford Withington , George Saklatvala , Michael P. Hobson

We study the angular power spectrum estimate in order to search for large scale anisotropies in the arrival directions distribution of the highest-energy cosmic rays. We show that this estimate can be performed even in the case of partial…

The future energy system will largely depend on volatile renewable energy sources and temperature-dependent loads, which makes the weather a central influencing factor. This article presents a novel approach for simulating weather scenarios…

Systems and Control · Electrical Eng. & Systems 2024-05-31 Jan Peper , David Kröger , Jonathan Kipp , Florian Ziel , Christian Rehtanz

I review some results of estimation of the power spectrum of density fluctuations from galaxy redshift surveys and discuss advances that may be possible with the Sloan Digital Sky Survey. I then examine the realities of power spectrum…

Astrophysics · Physics 2016-01-27 Michael S. Vogeley

Considering radio-interferometric observations, we present a fast and efficient estimator to compute the binned angular bispectrum (ABS) from gridded visibility data. The estimator makes use of Fast Fourier Transform (FFT) techniques to…

Cosmology and Nongalactic Astrophysics · Physics 2025-01-14 Sukhdeep Singh Gill , Somnath Bharadwaj , Sk. Saiyad Ali , Khandakar Md Asif Elahi

Next-generation spectroscopic surveys will map the large-scale structure of the observable universe, using emission line galaxies as tracers. While each survey will map the sky with a specific emission line, interloping emission lines can…

Cosmology and Nongalactic Astrophysics · Physics 2016-04-20 Anthony R. Pullen , Christopher M. Hirata , Olivier Dore , Alvise Raccanelli

By observing bright and compact astronomical sources while also taking data with the 183 GHz Water Vapour Radiometers, ALMA will be able to measure the `empirical' relationship between fluctuations in the phase of the astronomical signal…

Instrumentation and Methods for Astrophysics · Physics 2009-07-28 Bojan Nikolic

A maximum-likelihood method is presented for estimating the power spectrum of anisotropies in the cosmic microwave background (CMB) from interferometer observations. The method calculates flat band-power estimates in separate bins in…

Astrophysics · Physics 2009-11-07 M. P. Hobson , Klaus Maisinger

Detection of B-mode polarization of the cosmic microwave background (CMB) radiation is one of the frontiers of observational cosmology. Because they are an order of magnitude fainter than E-modes, it is quite a challenge to detect B-modes.…

Cosmology and Nongalactic Astrophysics · Physics 2013-01-23 Ata Karakci , P. M. Sutter , Le Zhang , Emory F. Bunn , Andrei Korotkov , Peter Timbie , Gregory S. Tucker , Benjamin D. Wandelt

We apply a pulsed-light interferometer to measure both the intensity and the phase of light that is transmitted through a strongly scattering disordered material. From a single set of measurements we obtain the time-resolved intensity,…

Disordered Systems and Neural Networks · Physics 2009-11-10 I. M. Vellekoop , P. Lodahl , A. Lagendijk

In radio astronomy, accurate calibration is of crucial importance for the new generation of radio interferometers. More specifically, because of the potential presence of outliers which affect the measured data, robustness needs to be…

Instrumentation and Methods for Astrophysics · Physics 2018-08-01 Virginie Ollier , Mohammed Nabil El Korso , André Ferrari , Rémy Boyer , Pascal Larzabal