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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…

天体物理学 · 物理学 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…

天体物理仪器与方法 · 物理学 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…

计算机视觉与模式识别 · 计算机科学 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…

天体物理仪器与方法 · 物理学 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…

天体物理仪器与方法 · 物理学 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…

天体物理仪器与方法 · 物理学 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…

计算机视觉与模式识别 · 计算机科学 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…

天体物理仪器与方法 · 物理学 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…

光学 · 物理学 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…

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…

天体物理仪器与方法 · 物理学 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…

图像与视频处理 · 电气工程与系统科学 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.…

天体物理学 · 物理学 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…

图像与视频处理 · 电气工程与系统科学 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…

天体物理仪器与方法 · 物理学 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…

计算机视觉与模式识别 · 计算机科学 2022-11-04 Ramtin Gharleghi , Dona Adikari , Katy Ellenberger , Mark Webster , Chris Ellis , Arcot Sowmya , Sze-Yuan Ooi , Susann Beier