English
Related papers

Related papers: Establishing Visible Interferometer System Respons…

200 papers

The application of precision interferometers is generally restricted to expensive and smooth high-quality surfaces. Here, we offer a route to ultimate miniaturization of interferometer by integrating beam splitter, reference mirror and…

Optics · Physics 2019-09-23 Pooja Munjal , Kamal P. Singh

In order to meet the theoretically achievable imaging performance, calibration of modern radio interferometers is a mandatory challenge, especially at low frequencies. In this perspective, we propose a novel parallel iterative…

Instrumentation and Methods for Astrophysics · Physics 2016-09-09 Martin Brossard , Mohammed Nabil El Korso , Marius Pesavento , Rémy Boyer , Pascal Larzabal , Stefan J. Wijnholds

Star surveys and model analyses show that many stars have absolute stable fluxes as good as 3% in 0.3-35{\mu}m wavebands and about 1% in the visible wavebands. The relative flux calibrations between stars are better than 0.2%. Some stars…

Instrumentation and Methods for Astrophysics · Physics 2017-07-10 Chun Xu

Imperfect photometric calibration of galaxy surveys due to either astrophysical or instrumental effects leads to biases in measuring galaxy clustering and in the resulting cosmological parameter measurements. More interestingly (and…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Dragan Huterer , Carlos E. Cunha , Wenjuan Fang

This study is concerned with the design of a Mueller imaging polarimeter for the visualization of spatially-varying Mueller matrix fields. A simplified calibration procedure is advocated, where all the optical elements are calibrated…

Instrumentation and Detectors · Physics 2018-11-08 Yvain Quéau , Florian Leporcq , Ayman Alfalou

The paper reviews progress in imaging in radio interferometry for the period 1993-1996. Unlike an optical telescope, the basic measurements of a radio interferometer (correlations between antennas) are indirectly related to a sky brightness…

Astrophysics · Physics 2007-05-23 R. J. Sault , T. A. Oosterloo

Stellar intensity interferometers correlate photons within their coherence time and could overcome the baseline limitations of existing amplitude interferometers. Intensity interferometers do not rely on phase coherence of the optical…

Instrumentation and Methods for Astrophysics · Physics 2022-02-24 Sebastian Karl , Andreas Zmija , Stefan Richter , Naomi Vogel , Dmitry Malyshev , Adrian Zink , Thilo Michel , Gisela Anton , Joachim von Zanthier , Stefan Funk

The optimization of integrated optical evanescent-wave sensors is dual. For optimal performances, we require waveguides with both maximal sensitivity to the measurand, the quantity intended to be measured, and minimal sensitivities to…

Optics · Physics 2014-04-16 Camille Delezoide , Isabelle Ledoux-Rak , Chi Thanh Nguyen

We propose a solution to the problem of astrometric and photometric calibration of coronagraphic images with a simple optical device which, in theory, is easy to use. Our design uses the Fraunhofer approximation of Fourier optics. Placing a…

Astrophysics · Physics 2008-11-26 Anand Sivaramakrishnan , Ben R. Oppenheimer

Several types of Wavefront Sensors (WFS) are nowadays available in the field of Adaptive Optics (AO). Generally speaking, their basic principle consists in measuring slopes or curvatures of Wavefront Errors (WFE) transmitted by a telescope,…

Optics · Physics 2011-05-17 Francois Henault

This paper studies the robustness of observability of a linear time-invariant system under sensor failures from a computational perspective. To be precise, the problem of determining the minimum number of sensors whose removal can destroy…

Optimization and Control · Mathematics 2023-07-18 Yuan Zhang , Yuanqing Xia , Kun Liu

As a consequence of the wave nature of light, invisibility devices based on isotropic media cannot be perfect. The principal distortions of invisibility are due to reflections and time delays. Reflections can be made exponentially small for…

Optics · Physics 2009-11-11 Ulf Leonhardt

In real telescopes, the optical parameters evolve with time, and the degradation is often not uniform. This introduces variations in the image profile and therefore photo-centre displacements which, unless corrected, may result in…

Astrophysics · Physics 2009-11-13 M. Gai , R. Cancelliere

We report on the design of an all-mirror wavefront-division interferometer capable of spectroscopic studies across multiple spectral ranges$\unicode{x2013}$from the plasma frequencies of metals to terahertz wavelengths and beyond. The…

In this paper, we argue that modern pre-integration methods for inertial measurement units (IMUs) are accurate enough to ignore the drift for short time intervals. This allows us to consider a simplified camera model, which in turn admits…

Computer Vision and Pattern Recognition · Computer Science 2022-08-18 Marcus Valtonen Örnhag , Patrik Persson , Mårten Wadenbäck , Kalle Åström , Anders Heyden

Visual photometry, the estimation of stellar brightness by eye, continues to provide valuable data even in this highly-instrumented era. However, the eye-brain system functions differently from electronic sensors and its products can be…

Instrumentation and Methods for Astrophysics · Physics 2024-01-02 Alan B. Whiting

Even-order dispersion cancellation, an effect previously identified with frequency-entangled photons, is demonstrated experimentally for the first time with a linear, classical interferometer. A combination of a broad bandwidth laser and a…

Quantum Physics · Physics 2009-11-13 K. J. Resch , P. Puvanathasan , J. S. Lundeen , M. W. Mitchell , K. Bizheva

In order to understand the positional uncertainties of arbitrary objects in several of the current major databases containing astrometric information, a sample of extragalactic radio sources with precise positions in the International…

Astrophysics · Physics 2009-10-31 Eric W. Deutsch

The high accuracy of modern space astrometry requires the use of General Relativity to model the propagation of stellar light through the gravitational field encountered from a source to a given observer inside the Solar System. In this…

General Relativity and Quantum Cosmology · Physics 2009-02-17 Mariateresa Crosta , Alberto Vecchiato

Interferometry provides one of the possible routes to ultra-high angular resolution for X-ray and gamma-ray astronomy. Sub-micro-arc-second angular resolution, necessary to achieve objectives such as imaging the regions around the event…

Instrumentation and Methods for Astrophysics · Physics 2009-07-31 G. K. Skinner , J. F. Krizmanic
‹ Prev 1 8 9 10 Next ›