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Related papers: De-biasing interferometric visibilities in VLTI-AM…

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We present in this paper an innovative data reduction method for single-mode interferometry. It has been specifically developed for the AMBER instrument, the three-beam combiner of the Very Large Telescope Interferometer, but can be derived…

Astrophysics · Physics 2009-11-11 E. Tatulli , the AMBER consortium

In order to put MIDI/VLTI observations of AGNs on a significant statistical basis, the number of objects had to be increased dramatically from the few prominent bright cases to over 20. For this, correlated fluxes as faint as ~ 150 mJy need…

Instrumentation and Methods for Astrophysics · Physics 2013-01-15 Leonard Burtscher , Konrad R. W. Tristram , Walter J. Jaffe , Klaus Meisenheimer

Since April 2011, realtime fringe tracking data are recorded simultaneously with data from the VLTI/AMBER interferometric beam combiner. Not only this offers possibilities to post-process AMBER reduced data to obtain more accurate…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 A. Merand , F. Patru , J. -P. Berger , I. Percheron , S. Poupar

We present here the current performances of the AMBER / VLTI instrument for standard use and compare these with the offered modes of the instrument. We show that the instrument is able to reach its specified precision only for medium and…

In optical interferometry, the visibility squared modulus are generally assumed to follow a Gaussian distribution and to be independent of each other. A quantitative analysis of the relevance of such assumptions is important to help…

Instrumentation and Methods for Astrophysics · Physics 2014-05-15 Antony Schutz , Martin Vannier , David Mary , Andre Ferrari , Florentin Millour , Romain Petrov

Measurement of interferometric parameters values is affected by phase disturbance due especially to atmospheric turbulences. Algorithms of fringe sensing, aimed at fringe parameters identification, are based on interferometric models that…

Instrumentation and Methods for Astrophysics · Physics 2009-08-27 Bonino Donata

This paper presents FairNVT, a lightweight debiasing framework for pretrained transformer-based encoders that improves both representation and prediction level fairness while preserving task accuracy. Unlike many existing debiasing…

Computer Vision and Pattern Recognition · Computer Science 2026-04-21 Qiaoyue Tang , Sepidehsadat Hosseini , Mengyao Zhai , Thibaut Durand , Greg Mori

Context: A turbulent atmosphere causes atmospheric piston variations leading to rapid changes in the optical path difference of an interferometer, which causes correlated flux losses. This leads to decreased sensitivity and accuracy in the…

Instrumentation and Methods for Astrophysics · Physics 2014-09-05 A. Müller , J. -U. Pott , A. Mérand , R. Abuter , F. Delplancke-Ströbele , Th. Henning , R. Köhler , Ch. Leinert , S. Morel , T. Phan Duc , E. Pozna , A. Ramirez , J. Sahlmann , C. Schmid

There are several solutions to code the signal arising from optical long baseline multi-aperture interferometers. In this paper,we focus on the {\bf non homothetic spatial coding scheme} (multiaxial) with the fringe pattern coded along one…

Astrophysics · Physics 2009-11-11 E. Tatulli , J. -B. LeBouquin

Interferometric observables are strongly correlated, yet it is common practice to ignore these correlations in the data analysis process. We develop an empirical model for the correlations present in Very Large Telescope Interferometer…

Instrumentation and Methods for Astrophysics · Physics 2021-01-04 Jens Kammerer , Antoine Mérand , Michael J. Ireland , Sylvestre Lacour

In Earth remote sensing, spatial-frequency domain visibility samples are inversely transformed into spatial-domain brightness temperature (BT) images through the signal processing pipeline of synthetic aperture interferometric radiometers…

Signal Processing · Electrical Eng. & Systems 2026-04-03 Yuankai Luo , Han Zhou , Jinlong Hao , Dong Zhu , Fei Hu

Interferometric observations with three telescopes or more provide two observables: closure phase information together with visibilities measurements. When using single-mode interferometers, both observables have to be redefined in the…

Astrophysics · Physics 2009-11-11 E. Tatulli , A. Chelli

The first astrophysical results of the VLTI focal instrument AMBER have shown the importance of the differential and closure phase measures, which are supposed to be much less sensitive to atmospheric and instrumental biases than the…

Astrophysics · Physics 2009-11-13 Florentin Millour , Romain Petrov , Martin Vannier , Stefan Kraus

Visibility estimators and their performance are presented for use with the Palomar Testbed Interferometer (PTI). One operational mode of PTI is single-baseline visibility measurement using pathlength modulation with synchronous readout by a…

Astrophysics · Physics 2009-10-31 M. M. Colavita

We present computer simulations of interferometric imaging with the Very Large Telescope Interferometer (VLTI) of the European Southern Observatory (ESO) and the Astronomical MultiBEam Recombiner (AMBER) phase-closure instrument. These…

Astrophysics · Physics 2015-06-24 F. Przygodda , T. Bloecker , K. -H. Hofmann , G. Weigelt

We present a new gravitational lens modelling technique designed to model high-resolution interferometric observations with large numbers of visibilities without the need to pre-average the data in time or frequency. We demonstrate the…

Instrumentation and Methods for Astrophysics · Physics 2021-01-06 Devon Powell , Simona Vegetti , John P. McKean , Cristiana Spingola , Francesca Rizzo , Hannah R. Stacey

Interferometers from the ground and space will be able to resolve the two images in a microlensing event. This will at least partially lift the inherent degeneracy between physical parameters in microlensing events. To increase the…

Astrophysics · Physics 2016-08-30 N. J. Rattenbury , S. Mao

VLT-Interferometry will allow imaging of the Galactic Center (GC) and the nuclei of extragalactic sources at an angular resolution of a few milliarcseconds. VLTI will be a prime instrument to study the immediate environment of the massive…

Astrophysics · Physics 2015-06-24 J. -U. Pott , A. Glindemann , A. Eckart , M. Schoeller , C. Leinert , T. Viehmann , M. Robberto

Nonlinear systems of affine control inputs overarch many sensor fusion instances. Analyzing whether a state variable in such a nonlinear system can be estimated (i.e., observability) informs better estimator design. Among the research on…

Systems and Control · Electrical Eng. & Systems 2022-07-19 Jianzhu Huai , Yukai Lin , Yujia Zhang

We present two algorithms to identify and flag radio frequency interference (RFI) in radio interferometric imaging data. The first algorithm utilizes the redundancy of visibilities inside a UV cell in the visibility plane to identify…

Instrumentation and Methods for Astrophysics · Physics 2018-06-27 Srikrishna Sekhar , Ramana Athreya
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