&lt;title&gt;VLT interferometer: proposed implementation&lt;/title&gt;

Beckers, J. M.; Enard, D.; Faucherre, M.; Merkle, F.; Benedetto, G.; Braun, Róbert; Foy, R.; Genzel, R.; Koechlin, Laurent; Weigelt, G.

doi:10.1117/12.19191

Cited by 11 publications

(8 citation statements)

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“…The VLTI entered its engineering phase in the early 1990's after its fundamental concept had been defined by the VLT interferometry panel 7,8 . This concept included the following elements recalled for the historical perspective:…”

Section: The Feasability Study and System Specification Phasementioning

confidence: 99%

A decade of VLTI technical development

Koehler¹,

Lévêque²,

Gitton³

2003

SPIE Proceedings

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Following the successful VLTI 'First Fringes' obtained in 2001 with the siderostats and with the 8m telescopes and based on the results from the commissioning phase, it is now possible to review with a critical eye the development approach followed over the last ten years and to draw a few conclusions.We first recall this approach that aimed at minimizing the risk of not meeting the stringent requirements imposed by interferometry. This approach is based on the elaboration of exhaustive error budgets, an extensive set of analyses and early tests with feedback on subsystem specs, the performance characterization at subsystem level with identification of improvements when needed; and finally the commissioning of the complete VLTI at system level.To illustrate this process, we provide practical examples taken from the project's history. We focus on two areas that have been considered among the most critical ones over the entire project life, namely: the turbulence inside the interferometer arms ('internal seeing') and the mechanical vibrations ('OPD stability').For these two areas, we will finally compare the performances predicted during the development phase with those obtained at Paranal and we will draw conclusions.

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Section: The Feasability Study and System Specification Phasementioning

confidence: 99%

A decade of VLTI technical development

Koehler¹,

Lévêque²,

Gitton³

2003

SPIE Proceedings

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“…The third, so-called modern era starts with the debut of the flagship facilities VLTI (Léna 1979, Beckers et al 1990, Schöller 2007, NASA Keck Interferometer (KI; Colavita et al 2013), CHARA (ten Brummelaar et al 2005), and LBTI (Defrère et al 2016), along with the evolution of NPOI. All of these facilities (except for the KI) are still operating as of 2022.…”

Section: Short History Of Optical/infrared Interferometrymentioning

confidence: 99%

Advances in Optical/Infrared Interferometry

Eisenhauer

Pfuhl

2023

Annual Review of Astronomy and Astrophysics

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After decades of fast-paced technical advances, optical/infrared (O/IR) interferometry has seen a revolution in recent years. ▪ The GRAVITY instrument at the Very Large Telescope Interferometer (VLTI) with four 8-m telescopes reaches thousand-times-fainter objects than possible with earlier interferometers, and the Center for High Angular Resolution Astronomy (CHARA) array routinely offers up to 330-m baselines and aperture-synthesis with six 1-m telescopes. ▪ The observed objects are fainter than 19 mag, the images have submilliarcsecond resolution, and the astrometry reaches microarcsecond precision. ▪ This led to breakthrough results on the Galactic Center, exoplanets, active galactic nuclei, young stellar objects, and stellar physics. Following a primer in interferometry, we summarize the advances that led to the performance boost of modern interferometers: ▪ Single-mode beam combiners now combine up to six telescopes, and image reconstruction software has advanced over earlier developments for radio interferometry. ▪ With a combination of large telescopes, adaptive optics (AO), fringe tracking, and especially dual-beam interferometry, GRAVITY has boosted the sensitivity by many orders of magnitudes. Another order-of-magnitude improvement will come from laser guide star AO. In combination with large separation fringe tracking, O/IR interferometry will then provide complete sky coverage for observations in the Galactic plane and substantial coverage for extragalactic targets. Expected final online publication date for the Annual Review of Astronomy and Astrophysics, Volume 61 is August 2023. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.

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“…A fast quad-cell wavefront sensor measures the wavefront tilt and adjusts it to equalise the flux in the four quadrants of the image formed by Fourier transforming and squaring the wavefront amplitude. This system of fast guiding is chosen to mimic the auto-guider used at COAST (Baldwin et al 1994a,b) and many other interferometers such as NPOI (Hutter, Elias & Hummel 1998) and the VLTI (Beckers et al 1990) auxiliary telescope array.…”

Section: Simulation Techniquesmentioning

confidence: 99%

Numerical simulations of pinhole and single-mode fibre spatial filters for optical interferometers

Keen¹,

Buscher²,

Warner³

2001

Monthly Notices RAS

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We use a numerical simulation to investigate the effectiveness of pinhole spatial filters at optical/IR interferometers and to compare them with single-mode optical fibre spatial filters and interferometers without spatial filters. We show that fringe visibility measurements in interferometers containing spatial filters are much less affected by changing seeing conditions than equivalent measurements without spatial filters. This reduces visibility calibration uncertainties, and hence can reduce the need for frequent observations of separate astronomical sources for calibration of visibility measurements. We also show that spatial filters can increase the signal-to-noise ratios of visibility measurements and that pinhole filters give signal-to-noise ratios within 17% of values obtained with single-mode fibres for aperture diameters up to 3r 0 . Given the simplicity of the use of pinhole filters we suggest that it represents a competitive, if not optimal, technique for spatial filtering in many current and next generation interferometers.

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<title>VLT interferometer: proposed implementation</title>

Cited by 11 publications

References 0 publications

A decade of VLTI technical development

A decade of VLTI technical development

Advances in Optical/Infrared Interferometry

Numerical simulations of pinhole and single-mode fibre spatial filters for optical interferometers

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