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Related papers: SFADI: the Speckle-Free Angular Differential Imagi…

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Context. The direct detection of exoplanets with high-contrast imaging requires advanced data processing methods to disentangle potential planetary signals from bright quasi-static speckles. Among them, angular differential imaging (ADI)…

Instrumentation and Methods for Astrophysics · Physics 2015-10-14 F. Cantalloube , D. Mouillet , L. M. Mugnier , J. Milli , O. Absil , C. A. Gomez Gonzalez , G. Chauvin , J. -L Beuzit , A. Cornia

Context. Spectroscopy of exoplanets is very challenging because of the high star-planet contrast. A technical difficulty in the design of imaging instruments is the noncommon path aberrations (NCPAs) between the adaptive optics (AO) sensing…

Instrumentation and Methods for Astrophysics · Physics 2019-11-06 Garima Singh , Raphaël Galicher , Pierre Baudoz , Olivier Dupuis , Manuel Ortiz , Axel Potier , Simone Thijs , Elsa Huby

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

High-contrast imaging (HCI) is one of the most challenging techniques for exoplanet detection. It relies on sophisticated data processing to reach high contrasts at small angular separations. Most data processing techniques of this type are…

Instrumentation and Methods for Astrophysics · Physics 2021-02-10 Carl-Henrik Dahlqvist , Olivier Absil

In High Contrast Imaging, a large instrumental, technological and algorithmic effort is made to reduce residual speckle noise and improve the detection capabilities. In this work, we explore the potential of using a precise physical…

Instrumentation and Methods for Astrophysics · Physics 2024-02-13 Dotan Gazith , Barak Zackay

The consortium of the Spectro-Polarimetric High-contrast Exoplanet REsearch installed at the Very Large Telescope (SPHERE/VLT) has been operating its guaranteed observation time (260 nights over five years) since February 2015. The main…

In direct imaging at high contrast, the bright glare produced by the host star makes the detection and the characterization of sub-stellar companions particularly challenging. In spite of the use of an extreme adaptive optics system…

Instrumentation and Methods for Astrophysics · Physics 2024-09-23 Olivier Flasseur , Théo Bodrito , Julien Mairal , Jean Ponce , Maud Langlois , Anne-Marie Lagrange

X-ray phase-contrast imaging has become indispensable for visualizing samples with low absorption contrast. In this regard, speckle-based techniques have shown significant advantages in spatial resolution, phase sensitivity, and…

Image and Video Processing · Electrical Eng. & Systems 2022-01-20 Zhi Qiao , Xianbo Shi , Yudong Yao , Michael J. Wojcik , Luca Rebuffi , Mathew J. Cherukara , Lahsen Assoufid

High-contrast imaging presents us with the opportunity to study circumstellar disks and the planets still embedded within them -- providing key insights into the formation and evolution of planetary systems. However, the post-processing…

Earth and Planetary Astrophysics · Physics 2022-08-31 Kellen Lawson , Thayne Currie , John Wisniewski , Tyler Groff , Michael McElwain , Joshua Schlieder

We demonstrate a compact, cost-effective snapshot spectral imaging system named Aperture Diffraction Imaging Spectrometer (ADIS), which consists only of an imaging lens with an ultra-thin orthogonal aperture mask and a mosaic filter sensor,…

Computer Vision and Pattern Recognition · Computer Science 2023-09-29 Tao Lv , Hao Ye , Quan Yuan , Zhan Shi , Yibo Wang , Shuming Wang , Xun Cao

There is a need for a cost-effective, quantitative imaging tool that can be deployed endoscopically to better detect early stage gastrointestinal cancers. Spatial frequency domain imaging (SFDI) is a low-cost imaging technique that produces…

Image and Video Processing · Electrical Eng. & Systems 2023-10-04 Jane Crowley , George S. D. Gordon

Direct imaging of exoplanets requires to separate the background noise from the exoplanet signals. Statistical methods have been recently proposed to avoid subtracting any signal of interest as opposed to initial self-subtracting methods…

Earth and Planetary Astrophysics · Physics 2024-12-02 Hadrien Cambazard , Nicolas Catusse , A. Chomez , A. -M. Lagrange

High-contrast imaging has afforded astronomers the opportunity to study light directly emitted by adolescent (tens of Myr) and ``proto" ($<$10Myr) planets still undergoing formation. Direct detection of these planets is enabled by empirical…

The direct imaging of extrasolar giant planets demands the highest possible contrasts (dH ~10 magnitudes) at the smallest angular separations (~0.1'') from the star. We present an adaptive optics observing method, called star-hopping,…

Earth and Planetary Astrophysics · Physics 2021-04-07 Z. Wahhaj , J. Milli , C. Romero , L. Cieza , A. Zurlo , A. Vigan , E. Peña , G. Valdes , F. Cantalloube , J. Girard , B. Pantoja

Context: High contrast imaging is a powerful technique to detect and characterize planetary companions at large orbital separations from their parent stars. Aims: We aim at studying the limiting magnitude of the VLT/SPHERE Adaptive Optics…

Instrumentation and Methods for Astrophysics · Physics 2022-11-30 M. I. Jones , J. Milli , I. Blanchard , Z. Wahhaj , R. de Rosa , C. Romero

Despite super-resolution fluorescence blinking microscopes break the diffraction limit, the intense phototoxic illumination and long-term image sequences thus far still pose to major challenges in visualizing live-organisms. Here, we…

This work proposes an innovative approach to improve Bragg coherent diffraction imaging (BCDI) microscopy applied to time evolving crystals and/or non-homogeneous crystalline strain fields, identified as two major limitations of BCDI…

Optics · Physics 2024-03-12 I. Calvo-Almazán , V. Chamard , T. Grünewald , M. Allain

The scarcity of annotated surgical data poses a significant challenge for developing deep learning systems in computer-assisted interventions. While diffusion models can synthesize realistic images, they often suffer from data memorization,…

Computer Vision and Pattern Recognition · Computer Science 2025-09-24 Danush Kumar Venkatesh , Stefanie Speidel

We aim at searching for exoplanets on the whole ESO/VLT-SPHERE archive with improved and unsupervised data analysis algorithm that could allow to detect massive giant planets at 5 au. To prepare, test and optimize our approach, we gathered…

Earth and Planetary Astrophysics · Physics 2023-07-26 A. Chomez , A. -M. Lagrange , P. Delorme , M. Langlois , G. Chauvin , O. Flasseur , J. Dallant , F. Philipot , S. Bergeon , D. Albert , N. Meunier , P. Rubini

Image Rotation and Subtraction (IRS) is a high-contrast imaging technique which can be used to suppress the speckles noise and facilitate the direct detection of exoplanets. IRS is different from Angular Differential Imaging (ADI), in which…

Instrumentation and Methods for Astrophysics · Physics 2015-06-23 Jiangpei Dou , Deqing Ren , Gang Zhao , Xi Zhang , Rui Chen , Yongtian Zhu