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

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In principle, suppression of on-axis stellar light by a coronagraph is easier on an unobscured aperture telescope than on one with an obscured aperture. Recent designs such as the apodized pupil Lyot coronagraph, the `band-limited' Lyot…

Astrophysics · Physics 2009-11-13 Anand Sivaramakrishnan , James P. Lloyd

The segmented pupil experiment for exoplanet detection (SPEED) facility aims to improve knowledge and insight into various areas required for gearing up high-contrast imaging instruments adapted to the unprecedented high angular resolution…

Instrumentation and Methods for Astrophysics · Physics 2021-03-19 K. Barjot , P. Martinez , M. Beaulieu , C. Gouvret , A. Marcotto , O. Guyon , M. Belhadi , A. Caillat , T. Behaghel , J. M. Le Duigou , K. Dohlen , A. Vigan

The vector vortex is a coronagraphic imaging mode of the recently commissioned Subaru Coronagraphic Extreme-Adaptive Optics (SCExAO) platform on the 8-m Subaru Telescope. This multi-purpose high-contrast visible and near-infrared (R- to…

Cardiac structure segmentation plays an important role in medical analysis procedures. Images' blurred boundaries issue always limits the segmentation performance. To address this difficult problem, we presented a novel network structure…

Computer Vision and Pattern Recognition · Computer Science 2019-07-03 Fei Feng , Jiajia Luo

Coronagraphs of the apodized pupil and shaped pupil varieties use the Fraunhofer diffraction properties of amplitude masks to create regions of high contrast in the vicinity of a target star. Here we present a hybrid coronagraph…

Instrumentation and Methods for Astrophysics · Physics 2016-01-21 Neil T. Zimmerman , A J Eldorado Riggs , N. Jeremy Kasdin , Alexis Carlotti , Robert J. Vanderbei

The optical vortex coronagraph (OVC) is one of the promising ways for direct imaging exoplanets because of its small inner working angle and high throughput. This paper presents the design and laboratory demonstration performance at 633nm…

Instrumentation and Methods for Astrophysics · Physics 2017-06-14 Chengchao Liu , Deqing Ren , Yongtian Zhu , Jiangpei Dou

The specification of polishing requirements for the optics in coronagraphs dedicated to exo-planet detection requires careful and accurate optical modelling. Numerical representations of the propagation of aberrations through the system as…

Instrumentation and Methods for Astrophysics · Physics 2011-11-07 Laurent Pueyo , N. Jeremy Kasdin , Stuart Shaklan

Convolutional neural networks (CNN) have had unprecedented success in medical imaging and, in particular, in medical image segmentation. However, despite the fact that segmentation results are closer than ever to the inter-expert…

Computer Vision and Pattern Recognition · Computer Science 2020-06-17 Nathan Painchaud , Youssef Skandarani , Thierry Judge , Olivier Bernard , Alain Lalande , Pierre-Marc Jodoin

The vector vortex coronagraph (VVC) performance in the laboratory and in ground-based observatories has earned it a spot on the NASA mission concepts HabEx and LUVOIR. The VVC induces a phase ramp through the manipulation of the…

Instrumentation and Methods for Astrophysics · Physics 2021-08-18 Jorge Llop-Sayson , Cole Kappel , Nemanja Jovanovic , Dimitri Mawet

We report on a soft route towards optical vortex coronagraphy based on self-engineered electrically tunable vortex masks based on liquid crystal topological defects. These results suggest that a nature-assisted technological approach to the…

Optics · Physics 2016-11-17 Artur Aleksanyan , Etienne Brasselet

We present a publicly available software package developed for exploring apodized pupil Lyot coronagraph (APLC) solutions for various telescope architectures. In particular, the package optimizes the apodizer component of the APLC for a…

As the performance of coronagraphs improves, the achievable contrast is more and more dependent of the shape of the pupil. The future generation of space and ground based coronagraphic instruments will have to achieve high contrast levels…

Instrumentation and Methods for Astrophysics · Physics 2017-10-11 Johan Mazoyer , Laurent Pueyo , Colin Norman , Mamadou N'Diaye , Dimitri Mawet , Rémi Soummer , Marshall Perrin , Élodie Choquet , Alexis Carlotti

We present recent laboratory results demonstrating high-contrast coronagraphy for the future space-based large IR/Optical/Ultraviolet telescope recommended by the Decadal Survey. The High-contrast Imager for Complex Aperture Telescopes…

The vector-Apodizing Phase Plate (vAPP) is a pupil-plane coronagraph that manipulates phase to create dark holes in the stellar PSF. The phase is induced on the circular polarization states through the inherently achromatic geometric phase…

Instrumentation and Methods for Astrophysics · Physics 2021-01-08 Steven P. Bos , David S. Doelman , Kelsey L. Miller , Frans Snik

Enhancing the precision of segmenting coronary atherosclerotic plaques from CT Angiography (CTA) images is pivotal for advanced Coronary Atherosclerosis Analysis (CAA), which distinctively relies on the analysis of vessel cross-section…

Image and Video Processing · Electrical Eng. & Systems 2025-01-15 Ziheng Zhang , Zihan Li , Dandan Shan , Yuehui Qiu , Qingqi Hong , Qingqiang Wu

A multitude of coronagraphic techniques for the space-based direct detection and characterization of exo-solar terrestrial planets are actively being pursued by the astronomical community. Typical coronagraphs have internal shaped focal…

This paper gives a simple and original presentation of various coronagraphs inherited from the Lyot coronagraph. We first present the Lyot and Roddier phase mask coronagraphs and study their properties as a function of the focal mask size.…

Astrophysics · Physics 2008-11-26 A. Ferrari , R. Soummer , C. Aime

Coronary Heart Disease (CHD) is a leading cause of death in the modern world. The development of modern analytical tools for diagnostics and treatment of CHD is receiving substantial attention from the scientific community. Deep…

Image and Video Processing · Electrical Eng. & Systems 2022-09-29 Maxim Popov , Temirgali Aimyshev , Eldar Ismailov , Ablay Bulegenov , Siamac Fazli

We present the concept of a binary shaped mask coronagraph applicable to a telescope pupil including obscuration, based on previous works on binary shaped pupil mask by \citet{Kasdin2005} and \citet{Vanderbei1999}. Solutions with…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 K. Enya , L. Abe

Computed Tomography Coronary Angiography (CTCA) is a non-invasive method to evaluate coronary artery anatomy and disease. CTCA is ideal for geometry reconstruction to create virtual models of coronary arteries. To our knowledge there is no…

Computer Vision and Pattern Recognition · Computer Science 2022-11-04 Ramtin Gharleghi , Dona Adikari , Katy Ellenberger , Mark Webster , Chris Ellis , Arcot Sowmya , Sze-Yuan Ooi , Susann Beier