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Related papers: Segmented coronagraph design and analysis (SCDA): …

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In this paper, we present the infrared coronagraphic test bench of the University of Li\`ege named VODCA (Vortex Optical Demonstrator for Coronagraphic Applications). The goal of the bench is to assess the performances of the Annular Groove…

Instrumentation and Methods for Astrophysics · Physics 2016-05-03 Aissa Jolivet , Pierre Piron , Elsa Huby , Olivier Absil , Christian Delacroix , Dimitri Mawet , Jean Surdej , Serge Habraken

Cardiac segmentation of atriums, ventricles, and myocardium in computed tomography (CT) images is an important first-line task for presymptomatic cardiovascular disease diagnosis. In several recent studies, deep learning models have shown…

Image and Video Processing · Electrical Eng. & Systems 2024-10-01 Sanguk Park , Minyoung Chung

The vortex coronagraph (VC) is a new generation small inner working angle (IWA) coronagraph currently offered on various 8-meter class ground-based telescopes. On these observing platforms, the current level of performance is not limited by…

Instrumentation and Methods for Astrophysics · Physics 2015-06-17 Dimitri Mawet , Laurent Pueyo , Alexis Carlotti , Bertrand Mennesson , Eugene Serabyn , James K. Wallace

The presence of plaques in the coronary arteries is a major risk to the patients' life. In particular, non-calcified plaques pose a great challenge, as they are harder to detect and more likely to rupture than calcified plaques. While…

For direct imaging of exoplanets, Scalar Vortex Coronagraphs (SVCs) are an attractive alternative to the popularly used Vector Vortex Coronagraphs (VVCs). This is primarily because they are able to induce the same phase ramp regardless of…

Instrumentation and Methods for Astrophysics · Physics 2022-05-24 Niyati Desai , Jorge Llop-Sayson , Nemanja Jovanovic , Garreth Ruane , Eugene Serabyn , Stefan Martin , Dimitri Mawet

An adaptive optics (AO) system based on stochastic parallel gradient descent (SPGD) algorithm is proposed to reduce the speckle noises in the optical system of stellar coronagraph in order to further improve the contrast. The principle of…

Instrumentation and Methods for Astrophysics · Physics 2015-05-28 Bing Dong , Deqing Ren , Xi Zhang

We introduce a new class of solutions for Apodized Pupil Lyot Coronagraphs (APLC) with segmented aperture telescopes to remove broadband diffracted light from a star with a contrast level of $10^{10}$. These new coronagraphs provide a key…

Instrumentation and Methods for Astrophysics · Physics 2016-03-09 Mamadou N'Diaye , Rémi Soummer , Laurent Pueyo , Alexis Carlotti , Christopher C. Stark , Marshall D. Perrin

The increasing complexity of the aperture geometry of the future space- and ground based-telescopes will limit the performance of the next generation of coronagraphic instruments for high contrast imaging of exoplanets. We propose here a…

Instrumentation and Methods for Astrophysics · Physics 2017-11-17 Johan Mazoyer , Laurent Pueyo , Mamadou N'Diaye , Kevin Fogarty , Lucie Leboulleux , Sylvain Egron , Colin Norman

Phase-induced amplitude apodization (PIAA) coronagraphs are a promising technology for imaging exoplanets, with the potential to detect Earth-like planets around Sun-like stars. A PIAA system nominally consists of a pair of mirrors which…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 E. Cady

Medical image segmentation often requires segmenting multiple elliptical objects on a single image. This includes, among other tasks, segmenting vessels such as the aorta in axial CTA slices. In this paper, we present a general approach to…

Image and Video Processing · Electrical Eng. & Systems 2022-06-22 Marin Benčević , Marija Habijan , Irena Galić , Danilo Babin

Over the last decade, the vector-apodizing phase plate (vAPP) coronagraph has been developed from concept to on-sky application in many high-contrast imaging systems on 8-m class telescopes. The vAPP is an geometric-phase patterned…

Properly apodized pupils can deliver point spread functions (PSFs) free of Airy rings, and are suitable for high dynamical range imaging of extrasolar terrestrial planets (ETPs). To reach this goal, classical pupil apodization (CPA)…

Astrophysics · Physics 2007-05-23 E. A. Pluzhnik , O. Guyon , S. T. Ridgway , F. Martinache , R. A. Woodruff , C. Blain , R. Galicher

High-contrast imaging and spectroscopy provide unique constraints for exoplanet formation models as well as for planetary atmosphere models. Instrumentation techniques in this field have greatly improved over the last two decades, with the…

Instrumentation and Methods for Astrophysics · Physics 2017-12-20 Johan Mazoyer , Laurent Pueyo , Mamadou N'Diaye , Kevin Fogarty , Neil Zimmerman , Rémi Soummer , Stuart Shaklan , Colin Norman

The spectroscopy of faint planetary-mass companions to nearby stars is one of the main challenges that new-generation high-contrast spectro-imagers are going to face. In a previous work we presented a long slit coronagraph (LSC), for which…

Instrumentation and Methods for Astrophysics · Physics 2013-07-12 A. Vigan , M. N'Diaye , K. Dohlen

The vector vortex coronagraph is an instrument designed for direct detection and spectroscopy of exoplanets over a broad spectral range. Our team is working towards demonstrating contrast performance commensurate with imaging temperate,…

Instrumentation and Methods for Astrophysics · Physics 2020-12-15 Garreth Ruane , Eugene Serabyn , Camilo Mejia Prada , Wesley Baxter , Eduardo Bendek , Dimitri Mawet , A J Eldorado Riggs

We present methods for optimizing pupil and focal plane optical elements that improve the performance of vortex coronagraphs on telescopes with obstructed or segmented apertures. Phase-only and complex masks are designed for the entrance…

Instrumentation and Methods for Astrophysics · Physics 2015-09-22 Garreth J. Ruane , Olivier Absil , Elsa Huby , Dimitri Mawet , Christian Delacroix , Brunella Carlomagno , Pierre Piron , Grover A. Swartzlander

We present a new instrument, the "Stellar Double Coronagraph" (SDC), a flexible coronagraphic platform. Designed for Palomar Observatory's 200" Hale telescope, its two focal and pupil planes allow for a number of different observing…

Instrumentation and Methods for Astrophysics · Physics 2016-06-24 Michael Bottom , J. Chris Shelton , James K. Wallace , Randall Bartos , Jonas Kuhn , Dimitri Mawet , Bertrand Mennesson , Rick Burruss , Eugene Serabyn

High contrast coronagraphic imaging is challenging for telescopes with central obstructions and thick spider vanes, such as the Subaru Telescope. We present in this paper the first laboratory demonstration of a high efficiency PIAA-type…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 Julien Lozi , Frantz Martinache , Olivier Guyon

Phase apodization coronagraphs are implemented in a pupil plane to create a dark hole in the science camera focal plane. They are successfully created as "Apodizing Phase Plates" (APPs) using classical optical manufacturing, and as…

Instrumentation and Methods for Astrophysics · Physics 2022-05-11 Matthew A. Kenworthy , Johanan L. Codona , Frans Snik

Providing closed and well-connected boundaries of coronary artery is essential to assist cardiologists in the diagnosis of coronary artery disease (CAD). Recently, several deep learning-based methods have been proposed for boundary…