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Related papers: Fourier phase analysis in radio-interferometry

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Recent interferometers (e.g. ALMA and NOEMA) allow us to obtain the detailed brightness distribution of the astronomical sources in 3 dimension (R.A., Dec., frequency). However, the interpixel correlation of the noise due to the limited uv…

Instrumentation and Methods for Astrophysics · Physics 2022-07-27 Takafumi Tsukui , Satoru Iguchi , Ikki Mitsuhashi , Kenichi Tadaki

Several strategies in phase retrieval are unified by an iterative "difference map" constructed from a pair of elementary projections and a single real parameter $\beta$. For the standard application in optics, where the two projections…

Numerical Analysis · Mathematics 2025-10-20 Veit Elser

Kernel phase interferometry is an approach to high angular resolution imaging which enhances the performance of speckle imaging with adaptive optics. Kernel phases are self-calibrating observables that generalize the idea of closure phases…

Instrumentation and Methods for Astrophysics · Physics 2016-09-21 Benjamin J. S. Pope

This paper proposes a novel structure-aware matrix completion framework assisted by radial basis function (RBF) interpolation for near-field radio map construction in extremely large multiple-input multiple-output (XL-MIMO) systems. Unlike…

Signal Processing · Electrical Eng. & Systems 2025-11-11 Hao Sun , Xianghao Yu , Junting Chen

The Atacama Large millimetre/submillimetre Array (ALMA) makes use of water vapour radiometers (WVR), which monitor the atmospheric water vapour line at 183 GHz along the line of sight above each antenna to correct for phase delays…

Instrumentation and Methods for Astrophysics · Physics 2017-09-20 L. T. Maud , R. P. J. Tilanus , T. A. van Kempen , M. R. Hogerheijde , M. Schmalzl , I. Yoon , Y. Contreras , M. C. Toribio , Y. Asaki , W. R. F. Dent , E. Fomalont , S. Matsushita

Direction of arrival (DOA) estimation is mostly performed using specialized arrays that have carefully designed receiver spacing and layouts to match the operating frequency range. In contrast, radio interferometric arrays are designed to…

Instrumentation and Methods for Astrophysics · Physics 2025-12-23 Sarod Yatawatta

The Atacama Millimeter/Submillimeter Array (ALMA) remains unparalleled in sensitivity at radio frequencies above 35 GHz. In this paper, we explore ALMA's potential for narrowband technosignature detection, considering factors such as the…

Instrumentation and Methods for Astrophysics · Physics 2024-12-02 Louisa A Mason , Michael A Garrett , Kelvin Wandia , Andrew P V Siemion

Phase retrieval is a nonlinear inverse problem that arises in a wide range of imaging modalities, from electron microscopy to Fourier ptychography. In particular, the reconstruction is facilitated when the sensing matrix is i.i.d. random,…

Differential phase observations with a near-IR interferometer offer a way to obtain spectra of extrasolar planets. The method makes use of the wavelength dependence of the interferometer phase of the planet/star system, which depends both…

Astrophysics · Physics 2015-06-24 Viki Joergens , Andreas Quirrenbach

Phase retrieval (PR), also sometimes referred to as quadratic sensing, is a problem that occurs in numerous signal and image acquisition domains ranging from optics, X-ray crystallography, Fourier ptychography, sub-diffraction imaging, and…

Machine Learning · Computer Science 2020-06-25 Namrata Vaswani

Radio interferometers observe the Fourier space of the sky, at locations determined by the array geometry. Before a real space image is constructed by a Fourier transform, the data is weighted to improve the quality of reconstruction. Two…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Sarod Yatawatta

A new technique for maintaining high contrast in an atom interferometer is used to measure large de Broglie wave phase shifts. Dependence of an interaction induced phase on the atoms' velocity is compensated by applying an engineered…

Quantum Physics · Physics 2009-11-10 Tony D. Roberts , Alexander D. Cronin , Martin V. Tiberg , David E. Pritchard

Radio observations at low frequencies with the Low Frequency Array (LOFAR) start discovering gigantic radio bridges connecting pairs of massive galaxy clusters. These observations probe unexplored mechanisms of in situ particle acceleration…

High Energy Astrophysical Phenomena · Physics 2020-02-19 G. Brunetti , F. Vazza

Phase estimation, at the heart of many quantum metrology and communication schemes, can be strongly affected by noise, whose amplitude may not be known, or might be subject to drift. Here, we investigate the joint estimation of a phase…

We address the problem of signal reconstruction from intensity measurements with respect to a measurement frame. This non-convex inverse problem is known as phase retrieval. The case considered in this paper concerns phaseless measurements…

Functional Analysis · Mathematics 2019-02-13 Goetz E. Pfander , Palina Salanevich

In this work we consider the problem of reconstruction of a signal from the magnitude of its Fourier transform, also known as phase retrieval. The problem arises in many areas of astronomy, crystallography, optics, and coherent diffraction…

Optics · Physics 2012-03-22 Eliyahu Osherovich

Any frequency selective device with an ongoing drift will cause observed spectra to be variously and simultaneously scaled in proportion to their source distances. The reason is that detectors after the drifting selection will integrate…

General Physics · Physics 2008-12-05 V. Guruprasad

With the construction of the VLTI (Very Large Telescope Interferometer of the European Observatory ESO for the southern hemisphere) it is now possible to make observations with resolutions of the order of milli-arc-seconds, especially in IR…

Solar and Stellar Astrophysics · Physics 2017-09-22 M. Hadjara

The development of new phased array systems in radio astronomy, as the low frequency array (LOFAR) and the square kilometre array (SKA), formed of a large number of small and flexible elementary antennas, has led to significant challenges.…

Next-generation radio interferometers, such as the Square Kilometre Array (SKA), will revolutionise our understanding of the universe through their unprecedented sensitivity and resolution. However, to realise these goals significant…

Instrumentation and Methods for Astrophysics · Physics 2017-11-20 Luke Pratley , Jason D. McEwen , Mayeul d'Avezac , Rafael E. Carrillo , Alexandru Onose , Yves Wiaux