English
Related papers

Related papers: Combining reference-star and angular differential …

200 papers

It is widely believed that adaptive optics only has a role in correcting turbulent wavefronts on large telescopes using very bright reference stars. Unfortunately these are very scarce and many astronomical targets require wavefront…

Instrumentation and Methods for Astrophysics · Physics 2019-11-19 Craig Mackay

Deep learning has shown great potential in accelerating diffusion tensor imaging (DTI). Nevertheless, existing methods tend to suffer from Rician noise and detail loss in reconstructing the DTI-derived parametric maps especially when…

Computer Vision and Pattern Recognition · Computer Science 2024-01-04 Wenxin Fan , Jian Cheng , Cheng Li , Xinrui Ma , Jing Yang , Juan Zou , Ruoyou Wu , Qiegen Liu , Shanshan Wang

Inversion by Direct Iteration (InDI) is a new formulation for supervised image restoration that avoids the so-called "regression to the mean" effect and produces more realistic and detailed images than existing regression-based methods. It…

Image and Video Processing · Electrical Eng. & Systems 2024-02-05 Mauricio Delbracio , Peyman Milanfar

[Abridged] Context. Spectral differential imaging (SDI) is part of the observing strategy of current and future high-contrast imaging instruments. It aims to reduce the stellar speckles that prevent the detection of cool planets by using…

Earth and Planetary Astrophysics · Physics 2014-07-02 A. -L. Maire , A. Boccaletti , J. Rameau , G. Chauvin , A. -M. Lagrange , M. Bonnefoy , S. Desidera , M. Sylvestre , P. Baudoz , R. Galicher , D. Mouillet

High-contrast imaging for the detection and characterization of exoplanets relies on the instrument's capability to block out the light of the host star. Some current post-processing methods for calibrating out the residual speckles use…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Marie Ygouf , Laurent M. Mugnier , David Mouillet , Thierry Fusco , Jean-Luc Beuzit

This work introduces a novel reinterpretation of structured illumination (SI) microscopy for coherent imaging that allows three-dimensional imaging of complex refractive index (RI). To do so, we show that coherent SI is mathematically…

Optics · Physics 2017-05-11 Shwetadwip Chowdhury , Will J. Eldridge , Adam Wax , Joseph A. Izatt

In long adaptive optics corrected exposures, exoplanet detections are currently limited by speckle noise originating from the telescope and instrument optics, and it is expected that such noise will also limit future high-contrast imaging…

Astrophysics · Physics 2009-11-13 C. Marois , D. Lafreniere , B. Macintosh , R. Doyon

Prostate cancer (PCa) is the second most common cancer in men worldwide and the most frequently diagnosed cancer among men in more developed countries. The prognosis of PCa is excellent if detected at an early stage, making early screening…

Medical Physics · Physics 2021-09-14 Alexander Wong , Hayden Gunraj , Vignesh Sivan , Masoom A. Haider

Optical microscopy has been employed to derive salient characteristics of an object in various fields, including cell biology, flow cytometry, biopsy, and neuroscience. In particular, measuring the phase of light scattered from an object…

Optics · Physics 2025-03-18 Jeonghun Oh , Herve Hugonnet , Weisun Park , YongKeun Park

Most neighboring stars are still detected as point sources and are beyond the angular resolution reach of current observatories. Methods to improve our understanding of stars at high angular resolution are investigated. Air Cherenkov…

Instrumentation and Methods for Astrophysics · Physics 2012-09-07 Paul D. Nunez

In February 2014, the SHARK-VIS (System for High contrast And coronography from R to K at VISual bands) Forerunner, a high contrast experimental imager operating at visible wavelengths, was installed at LBT (Large Binocular Telescope). Here…

Instrumentation and Methods for Astrophysics · Physics 2017-08-09 F. Pedichini , M. Stangalini , A. Ambrosino , A. Puglisi , E. Pinna , V. Bailey , L. Carbonaro , M. Centrone , J. Christou , S. Esposito , J. Farinato , F. Fiore , E. Giallongo , J. M. Hill , P. M. Hinz , L. Sabatini

Direct detection and spectroscopy of exoplanets requires high contrast imaging. For habitable exoplanets in particular, located at small angular separation from the host star, it is crucial to employ small inner working angle (IWA)…

Instrumentation and Methods for Astrophysics · Physics 2016-11-09 P. Pathak , O. Guyon , N. Jovanovic , J. Lozi , F. Martinache , Y. Minowa , T. Kudo , H. Takami , Y. Hayano , N. Narita

The Planetary Systems Imager (PSI) is a proposed instrument for the Thirty Meter Telescope (TMT) that provides an extreme adaptive optics (AO) correction to a multi-wavelength instrument suite optimized for high contrast science. PSI's…

We present a method for speckle holography that is optimised for crowded fields. Its two key features are an iterativ improvement of the instantaneous Point Spread Functions (PSFs) extracted from each speckle frame and the (optional)…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 R. Schoedel , S. Yelda , A. Ghez , J. H. V. Girard , L. Labadie , R. Rebolo , A. Perez-Garrido , M. R. Morris

Current and future high contrast imaging instruments aim to detect exoplanets at closer orbital separations, lower masses, and/or older ages than their predecessors. However, continually evolving speckles in the coronagraphic science image…

Instrumentation and Methods for Astrophysics · Physics 2022-06-22 Benjamin L. Gerard , Daren Dillon , Sylvain Cetre , Rebecca Jensen-Clem

Deep subspace clustering methods are now prominent in clustering, typically using fully connected networks and a self-representation loss function. However, these methods often struggle with overfitting and lack interpretability. In this…

Computer Vision and Pattern Recognition · Computer Science 2024-06-24 Xianlu Li , Nicolas Nadisic , Shaoguang Huang , Aleksandra Pižurica

X-ray phase contrast imaging (XPCI) provides higher sensitivity to contrast between low absorbing objects that can be invisible to conventional attenuation-based X-ray imaging. XPCI's main application has been so far focused on medical…

High-dispersion coronagraphy (HDC) optimally combines high contrast imaging techniques such as adaptive optics/wavefront control plus coronagraphy to high spectral resolution spectroscopy. HDC is a critical pathway towards fully…

To image faint substellar companions obscured by the stellar halo and speckles, scattered light from the bright primary star must be removed in hardware or software. We apply the "locally-optimized combination of images" (LOCI) algorithm to…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Katie M. Morzinski , Bruce A. Macintosh , Laird M. Close , Christian Marois , Quinn Konopacky , Jenny Patience

Illuminating or imaging samples from a broad angular range is essential in a wide variety of computational 3D imaging and resolution-enhancement techniques, such as optical projection tomography (OPT), optical diffraction tomography (ODT),…