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Holography is an established technique for measuring the wavefront of optical signals through interferometric combination with a reference wave. Conventionally the integration time of a hologram is limited by the interferometer coherence…

Optics · Physics 2023-12-13 Guillaume Thekkadath , Duncan England , Benjamin Sussman

Radio-astronomical observations are increasingly contaminated by interference, and suppression techniques become essential. A powerful candidate for interference mitigation is adaptive spatial filtering. We study the effect of spatial…

Astrophysics · Physics 2014-10-13 Amir Leshem , Alle-Jan van der Veen

We augment the two widest/deepest 1.4 GHz radio surveys: the NRAO VLA Sky Survey (NVSS) and the Faint Images of the Radio Sky at Twenty-Centimeters (FIRST), with the mean epoch in which each source was observed. We use these catalogs to…

Astrophysics of Galaxies · Physics 2015-05-28 Eran O. Ofek , Dale A. Frail

In this article I briefly describe how deep radio surveys may provide a means to identify variations in the upper end of the initial mass function (IMF) in star-forming galaxies at high redshifts (i.e., $z\gtrsim$3). At such high redshifts,…

Cosmology and Nongalactic Astrophysics · Physics 2010-09-10 Eric J. Murphy

The design of an interferometric array should allow optimal instrumental response regarding all possible source positions, times of integration and scientific goals. It should also take into account constraints such as forbidden regions on…

Astrophysics · Physics 2009-11-07 F. Boone

By analysing the radio emissions from air showers using interferometry, we can estimate their properties. In this contribution, we apply interferometry to reconstruct air-shower parameters based on measurements taken with the Auger…

Instrumentation and Methods for Astrophysics · Physics 2025-09-08 Pim van Dillen

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.…

Radio interferometry is the current method of choice for deep space astronomy, but in the past few decades optical techniques have become increasingly common. This research seeks to characterize the performance of aperture masking…

Instrumentation and Methods for Astrophysics · Physics 2020-08-28 Kyle Morgenstein

Recent developments in astronomical radio telescopes opened new opportunities in imaging and spectroscopy of solar radio bursts at sub-second timescales. Imaging in narrow frequency bands has revealed temporal variations in the positions…

Solar and Stellar Astrophysics · Physics 2020-12-16 Xingyao Chen , Eduard P. Kontar , Nicolina Chrysaphi , Natasha L. S. Jeffrey , Mykola Gordovskyy , Yihua Yan , Baolin Tan

Astronomical optical interferometers sample the Fourier transform of the intensity distribution of a source at the observation wavelength. Because of rapid perturbations caused by atmospheric turbulence, the phases of the complex Fourier…

Instrumentation and Methods for Astrophysics · Physics 2014-10-07 Antony Schutz , André Ferrari , David Mary , Férréol Soulez , Éric Thiébaut , Martin Vannier

Higher spatial resolution and larger imaging scene are always the goals pursued by advanced space-borne SAR system.High resolution and wide swath SAR imaging can provide more information about the illuminated scene of interest on one…

Signal Processing · Electrical Eng. & Systems 2024-02-27 Xinhua Mao

Interstellar scintillation can be used to probe transverse sizes of radio sources on scales inaccessible to the nominal resolution of any terrestrial telescope, e.g. $\lesssim 10^{-6}$ arc sec. Methodology is presented that exploits this…

Astrophysics · Physics 2007-05-23 J. M. Cordes

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

Interferometers play an increasingly important role for spatially resolved observations. If employed at full potential, interferometry can probe an enormous dynamic range in spatial scale. Interpretation of the observed visibilities…

Instrumentation and Methods for Astrophysics · Physics 2015-06-19 C. Brinch , C. P. Dullemond

Microturbulence, i.e. enhanced fluctuations of plasma density, electric and magnetic fields, is of great interest in astrophysical plasmas, but occurs on spatial scales far too small to resolve by remote sensing, e.g., at ~ 1-100 cm in the…

Astrophysics · Physics 2009-11-13 Gelu M. Nita , Dale E. Gary , Gregory D. Fleishman

The fidelity of radio astronomical images is generally assessed by practical experience, i.e. using rules of thumb, although some aspects and cases have been treated rigorously. In this paper we present a mathematical framework capable of…

Instrumentation and Methods for Astrophysics · Physics 2010-03-12 Stefan J. Wijnholds , Alle-Jan van der Veen

We study the impact of the spread spectrum effect in radio interferometry on the quality of image reconstruction. This spread spectrum effect will be induced by the wide field-of-view of forthcoming radio interferometric telescopes. The…

Instrumentation and Methods for Astrophysics · Physics 2013-01-31 Laura Wolz , Filipe B. Abdalla , Rafael E. Carrillo , Yves Wiaux , Jason D. McEwen

We describe a new algorithm for reconstruction of Differential Emission Measures (DEMs) in the solar corona. Although a number of such algorithms currently exist, they can have difficulty converging for some cases, and can be complex, slow,…

Solar and Stellar Astrophysics · Physics 2020-12-11 Joseph Plowman , Amir Caspi

Radio observations from space allow to characterize solar radio bursts below the ionospheric cutoff, which are otherwise inaccessible, but suffer from low, insufficient temporal resolution. In this Letter we present novel, high-temporal…

Solar and Stellar Astrophysics · Physics 2024-10-25 Antonio Vecchio , Milan Maksimovic , Nicolina Chrysaphi , Eduard P. Kontar , Vratislav Krupar

Metric and decametric radio-emissions from the Sun are the only direct source of information about the dynamics of non-thermal electrons in the upper corona. In addition, the combination of spectral and imaging (sizes, shapes, and…

Solar and Stellar Astrophysics · Physics 2022-02-09 M. Gordovskyy , E. P. Kontar , D. L. Clarkson , N. Chrysaphi , P. K. Browning