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Related papers: Phase-Apodized-Pupil Lyot Coronagraphs for Arbitra…

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Focused plenoptic cameras can record spatial and angular information of the light field (LF) simultaneously with higher spatial resolution relative to traditional plenoptic cameras, which facilitate various applications in computer vision.…

Computer Vision and Pattern Recognition · Computer Science 2023-05-02 Kedeng Tong , Xin Jin , Yuqing Yang , Chen Wang , Jinshi Kang , Fan Jiang

In recent years, phase mask coronagraphy has become increasingly efficient in imaging the close environment of stars, enabling the search for exoplanets and circumstellar disks. Coronagraphs are ideally suited instruments, characterized by…

Instrumentation and Methods for Astrophysics · Physics 2014-12-02 Christian Delacroix , Oliver Absil , Dimitri Mawet , Charles Hanot , Mikael Karlsson , Pontus Forsberg , Eric Pantin , Jean Surdej , Serge Habraken

Optical imperfections, misalignments, aberrations, and even dust can significantly limit sensitivity in high-contrast imaging systems such as coronagraphs. An upstream deformable mirror (DM) in the pupil can be used to correct or compensate…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Johanan L. Codona , Matthew Kenworthy

Context. The Annular Groove Phase Mask (AGPM) is one possible implementation of the vector vortex coronagraph, where the helical phase ramp is produced by a concentric subwavelength grating. For several years, we have been manufacturing…

Aspl\"und 's metric, which is useful for pattern matching, consists in a double-sided probing, i.e. the over-graph and the sub-graph of a function are probed jointly. This paper extends the Aspl\"und 's metric we previously defined for…

Computer Vision and Pattern Recognition · Computer Science 2017-02-28 Guillaume Noyel , Michel Jourlin

We report the use of a phase retrieval procedure based on maximum likelihood estimation (MLE) to produce an improved, experimentally calibrated model of a point spread function (PSF) for use in three-dimensional (3D) localization microscopy…

Optics · Physics 2017-05-30 Petar N. Petrov , Yoav Shechtman , W. E. Moerner

The detection and characterization of extrasolar planets with SPHERE (Spectro Polarimetric High contrast Exoplanet REsearch) is challenging and in particular relies on the ability of a coronagraph to attenuate the diffracted starlight.…

We propose a new fast algorithm for solving one of the standard approaches to ill-posed linear inverse problems (IPLIP), where a (possibly non-smooth) regularizer is minimized under the constraint that the solution explains the observations…

Optimization and Control · Mathematics 2012-10-10 Manya V. Afonso , José M. Bioucas-Dias , Mário A. T. Figueiredo

Electronic health records contain rich textual data which possess critical predictive information for machine-learning based diagnostic aids. However many traditional machine learning methods fail to simultaneously integrate both vector…

Machine Learning · Computer Science 2012-07-31 Thomas Perry , Hongyuan Zha , Patricio Frias , Dadan Zeng , Mark Braunstein

Detection and characterization of exoplanets by direct imaging requires a coronagraph designed to deliver high contrast at small angular separation. To achieve this, an accurate control of low order aberrations, such as pointing and focus…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 Frédéric P. A. Vogt , Frantz Martinache , Olivier Guyon , Takashi Yoshikawa , Kaito Yokochi , Vincent Garrel , Taro Matsuo

The band-limited coronagraph is a nearly ideal concept that theoretically enables perfect cancellation of all the light of an on-axis source. Over the past years, several prototypes have been developed and tested in the laboratory, and more…

Instrumentation and Methods for Astrophysics · Physics 2015-06-03 P. Martinez , C. Dorrer , M. Kasper

Optical beams and starlight distorted by atmospheric turbulence can be corrected with adaptive optics systems to enable efficient coupling into single-mode fibers. Deformable mirrors, used to flatten the wavefront in astronomical…

Recently, we have used, pulsar polarisation datasets, on circular polarisation degree & linear polarisation position angle, to relate with well established theories, on ellipticity parameter and linear polarisation position angles, accrued…

High Energy Astrophysical Phenomena · Physics 2020-01-22 Karam Chand , Subhayan Mandal

Microlens parallax measurements combining space-based and ground-based observatories can be used to study planetary demographics. In recent years, the Spitzer Space Telescope was used as a microlens parallax satellite. Meanwhile,…

Earth and Planetary Astrophysics · Physics 2020-08-12 Lisa Dang , Sebastiano Calchi Novati , Sean Carey , Nicolas B. Cowan

We performed an experimental verification of a coronagraph. As a result, we confirmed that, at the focal region where the planetary point spread function exists, the coronagraph system mitigates the raw contrast of a star-planet system by…

Earth and Planetary Astrophysics · Physics 2023-07-12 Satoshi Itoh , Taro Matsuo , Shunsuke Ota , Kensuke Hara , Yuji Ikeda , Reiki Kojima , Toru Yamada , Takahiro Sumi

Quasi-static aberrations in coronagraphic systems are the ultimate limitation to the capabilities of exoplanet imagers both ground-based and space-based. These aberrations - which can be due to various causes such as optics alignment or…

Instrumentation and Methods for Astrophysics · Physics 2019-07-31 Olivier Herscovici-Schiller , Jean-François Sauvage , Laurent M. Mugnier , Kjetil Dohlen , Arthur Vigan

We propose a coronagraphic system with fourth-order null for off-axis segmented telescopes, which is sufficiently insensitive to the telescope pointing errors and finite angular diameter of the host star to enable high-contrast imaging of…

Instrumentation and Methods for Astrophysics · Physics 2020-05-06 Satoshi Itoh , Taro Matsuo

We describe the design and initial results from a visible-light Lyot coronagraph for SCExAO/VAMPIRES. The coronagraph is comprised of four hard-edged, partially transmissive focal plane masks with inner working angles of 36 mas, 55 mas, 92…

Instrumentation and Methods for Astrophysics · Physics 2022-08-05 Miles Lucas , Michael Bottom , Olivier Guyon , Julien Lozi , Barnaby Norris , Vincent Deo , Sebastien Vievard , Kyohoon Ahn , Nour Skaf , Peter Tuthill

Gaussian aperture pupil masks (GAPMs) can in theory achieve the contrast requisite for directly imaging an extrasolar planet around a nearby solar type star. We outline the process of designing, fabricating, and testing a GAPM for use on…

Astrophysics · Physics 2009-11-10 J. H. Debes , J. Ge

We study the \emph{Proximal Alternating Predictor-Corrector} (PAPC) algorithm introduced recently by Drori, Sabach and Teboulle to solve nonsmooth structured convex-concave saddle point problems consisting of the sum of a smooth convex…

Optimization and Control · Mathematics 2018-09-24 D. Russell Luke , Ron Shefi
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