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Observations of the Sun from the Earth are always limited by the presence of the atmosphere, which strongly disturbs the images. A solution to this problem is to place the telescopes in space satellites, which produce observations without…

Solar and Stellar Astrophysics · Physics 2015-06-24 C. Quintero Noda , A. Asensio Ramos , D. Orozco Suárez , B. Ruiz Cobo

Intensity mapping is a promising technique for surveying the large scale structure of our Universe from $z=0$ to $z \sim 150$, using the brightness temperature field of spectral lines to directly observe previously unexplored portions of…

Cosmology and Nongalactic Astrophysics · Physics 2016-12-21 Adrian Liu , Yunfan Zhang , Aaron R. Parsons

We present a procedure for efficiently compressing astronomical radio data for high performance applications. Integrated, post-correlation data are first passed through a nearly lossless rounding step which compares the precision of the…

In this paper, we apply our sky map reconstruction method for transit type interferometers to the Tianlai cylinder array. The method is based on the spherical harmonic decomposition, and can be applied to cylindrical array as well as dish…

Instrumentation and Methods for Astrophysics · Physics 2016-10-12 Jiao Zhang , Shifan Zuo , Reza Ansari , Xuelei Chen , Yichao Li , Fengquan Wu , Jean-Eric Campagne , Christophe Magneville

We present a framework for the optimal filtering of spherical signals contaminated by realizations of an additive, zero-mean, uncorrelated and anisotropic noise process on the sphere. Filtering is performed in the wavelet domain given by…

Signal Processing · Electrical Eng. & Systems 2021-02-09 Adeem Aslam , Zubair Khalid , Jason D. McEwen

In this paper, we describe the principle of a multi-aperture interferometer that uses a phase-shifting technique and is suitable for quick, snapshot imaging of astrophysical objects at extreme angular resolution through Fourier inversion. A…

Optics · Physics 2015-05-28 Francois Henault

We present in this letter a scheme for optical interferometry. We utilize coherent-beam-stimulated two-mode squeezed light, which interacts with a phase shifter and is then squeezed again before detection. Our theoretical device has the…

Quantum Physics · Physics 2015-06-16 William N. Plick , Jonathan P. Dowling , G. S. Agarwal

Galactic all-sky maps at very disparate frequencies, like in the radio and $\gamma$-ray regime, show similar morphological structures. This mutual information reflects the imprint of the various physical components of the interstellar…

A measurement of the cosmological 21 cm signal remains a promising but as-of-yet unattained ambition of radio astronomy. A positive detection would provide direct observations of key unexplored epochs of our cosmic history, including the…

Cosmology and Nongalactic Astrophysics · Physics 2015-08-18 Morgan Presley , Adrian Liu , Aaron Parsons

We describe a monolithic interferometer for spatial coherence measurements of both classical and quantum light sources. The design combines parametric down-conversion with a thermal source, using two identical calcite crystals to control…

Sky models have been used in the past to calibrate individual low radio frequency telescopes. Here we generalize this approach from a single antenna to a two element interferometer and formulate the problem in a manner to allow us to…

Instrumentation and Methods for Astrophysics · Physics 2017-06-28 Divya Oberoi , Rohit Sharma , Alan E. E. Rogers

The Fourier-Transform ghost imaging of both amplitude-only and pure-phase objects was experimentally observed with classical incoherent light at Fresnel distance by a new lensless scheme. The experimental results are in good agreement with…

Quantum Physics · Physics 2015-06-26 Minghui Zhang , Qing Wei , Xia Shen , Yongfeng Liu , Honglin Liu , Jing Cheng , Shensheng Han

Utilizing spherical harmonic (SH) domain has been established as the default method of obtaining continuity over space in head-related transfer functions (HRTFs). This paper concerns different variants of extending this solution by…

Audio and Speech Processing · Electrical Eng. & Systems 2023-07-19 Adam Szwajcowski

We present an investigation of the horizon and its effect on global 21-cm observations and analysis. We find that the horizon cannot be ignored when modeling low frequency observations. Even if the sky and antenna beam are known exactly,…

Cosmology and Nongalactic Astrophysics · Physics 2021-12-15 Neil Bassett , David Rapetti , Keith Tauscher , Bang D. Nhan , David D. Bordenave , Joshua J. Hibbard , Jack O. Burns

We show that with spatially incoherent illumination, the point spread function width of an imaging interferometer like that used in full-field optical coherence tomography (FFOCT) is almost insensitive to aberrations that mostly induce a…

Optics · Physics 2016-08-16 Peng Xiao , Mathias Fink , A. Claude Boccara

We introduce a convenient formalism to evaluate the frequency-shift affecting a light signal propagating on a general curved background. Our formulation, which is based on the laws of geometric optics in a general relativistic setting,…

General Relativity and Quantum Cosmology · Physics 2020-06-02 Daniel R. Terno , Giuseppe Vallone , Francesco Vedovato , Paolo Villoresi

The CLEAN algorithm, widely used in radio interferometry for the deconvolution of radio images, performs well only if the raw radio image (dirty image) is, to good approximation, a simple convolution between the instrumental point-spread…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 I. M. Stewart , D. M. Fenech , T. W. B. Muxlow

We describe and compare several post-correlation radio frequency interference classification methods. As data sizes of observations grow with new and improved telescopes, the need for completely automated, robust methods for radio frequency…

Instrumentation and Methods for Astrophysics · Physics 2010-07-14 A. R. Offringa , A. G. de Bruyn , M. Biehl , S. Zaroubi , G. Bernardi , V. N. Pandey

Simulated maps of the microwave background (CMB) radiation are generally created using one of two methods: all-sky simulations use the spherical harmonic transform, while maps covering small areas approximate the sky as flat, allowing the…

Cosmology and Nongalactic Astrophysics · Physics 2025-07-22 Mariona Giner Mascarell , Emory F. Bunn

The SkyMapper 1.3 m telescope at Siding Spring Observatory has now begun regular operations. Alongside the Southern Sky Survey, a comprehensive digital survey of the entire southern sky, SkyMapper will carry out a search for supernovae and…

Instrumentation and Methods for Astrophysics · Physics 2017-07-26 Richard Scalzo , Fang Yuan , Michael J. Childress , Anais Moller , Brian Schmidt , Brad E. Tucker , Bonnie Zhang , Pierre Astier , Marc Betoule , Nicolas Regnault
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