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Context. The next generation of space-borne instruments dedicated to the direct detection of exoplanets requires unprecedented levels of wavefront control precision. Coronagraphic wavefront sensing techniques for these instruments must…

Instrumentation and Methods for Astrophysics · Physics 2018-07-20 Olivier Herscovici-Schiller , Laurent M. Mugnier , Pierre Baudoz , Raphaël Galicher , Jean-François Sauvage , Baptiste Paul

Continuous wavefront sensing on future space telescopes allows relaxation of stability requirements while still allowing on-orbit diffraction-limited optical performance. We consider the suitability of phase retrieval to continuously…

Instrumentation and Methods for Astrophysics · Physics 2023-09-14 Hyukmo Kang , Kyle Van Gorkom , Jess Johnson , Ole Singlestad , Aaron Goldtooth , Daewook Kim , Ewan S. Douglas

The PIAA is a now well demonstrated high contrast technique that uses an intermediate remapping of the pupil for high contrast coronagraphy (apodization), before restoring it to recover classical imaging capabilities. This paper presents…

Instrumentation and Methods for Astrophysics · Physics 2015-06-05 Frantz Martinache , Olivier Guyon , Christophe Clergeon , Celia Blain

Multi-Agent Proximal Policy Optimization (MAPPO) is a variant of the Proximal Policy Optimization (PPO) algorithm, specifically tailored for multi-agent reinforcement learning (MARL). MAPPO optimizes cooperative multi-agent settings by…

Machine Learning · Computer Science 2026-05-14 Changha Lee , Gyusang Cho

The quality of images of the Sun obtained from the ground are severely limited by the perturbing effect of the turbulent Earth's atmosphere. The post-facto correction of the images to compensate for the presence of the atmosphere require…

Solar and Stellar Astrophysics · Physics 2018-12-05 A. Asensio Ramos , J. de la Cruz Rodriguez , A. Pastor Yabar

This paper proposes an automated method to detect, group and rectify arbitrarily-arranged coplanar repeated elements via energy minimization. The proposed energy functional combines several features that model how planes with coplanar…

Computer Vision and Pattern Recognition · Computer Science 2017-11-29 James Pritts , Denys Rozumnyi , M. Pawan Kumar , Ondrej Chum

The success of ground-based instruments for high contrast exoplanet imaging depends on the degree to which adaptive optics (AO) systems can mitigate atmospheric turbulence. While modern AO systems typically suffer from millisecond time lags…

Instrumentation and Methods for Astrophysics · Physics 2019-09-13 Rebecca Jensen-Clem , Charlotte Z. Bond , Sylvain Cetre , Eden McEwen , Peter Wizinowich , Sam Ragland , Dimitri Mawet , James Graham

The Magellan extreme adaptive optics (MagAO-X) instrument is a new extreme adaptive optics (ExAO) system designed for operation in the visible to near-IR which will deliver high contrast-imaging capabilities. The main AO system will be…

We present the results obtained with an end-to-end simulator of an Extreme Adaptive Optics (XAO) system control loop. It is used to predict its on-sky performances and to optimise the AO loop algorithms. It was first used to validate a…

Instrumentation and Methods for Astrophysics · Physics 2023-01-10 Anthony Berdeu , Michel Tallon , Éric Thiébaut , Mary Angelie Alagao , Sitthichat Sukpholtham , Maud Langlois , Adithep Kawinkij , Puttiwat Kongkaew

The next generation of ground-based instruments aims to break through the knowledge we have on exoplanets by imaging circumstellar environments always closer to the stars. However, direct imaging requires an AO system and high-contrast…

Instrumentation and Methods for Astrophysics · Physics 2019-10-22 A. Potier , P. Baudoz , R. Galicher , E. Huby , G. Singh

One of the key noise sources that currently limits high-contrast imaging observations for exoplanet detection is quasi-static speckles. Quasi-static speckles originate from slowly evolving non-common path aberrations (NCPA). The purpose of…

Instrumentation and Methods for Astrophysics · Physics 2021-09-08 S. P. Bos , K. L. Miller , J. Lozi , O. Guyon , D. S. Doelman , S. Vievard , A. Sahoo , V. Deo , N. Jovanovic , F. Martinache , T. Currie , F. Snik

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

Adjusting camera exposure in arbitrary lighting conditions is the first step to ensure the functionality of computer vision applications. Poorly adjusted camera exposure often leads to critical failure and performance degradation.…

Computer Vision and Pattern Recognition · Computer Science 2024-04-03 Kyunghyun Lee , Ukcheol Shin , Byeong-Uk Lee

No-reference point cloud quality assessment (NR-PCQA) aims to automatically evaluate the perceptual quality of distorted point clouds without available reference, which have achieved tremendous improvements due to the utilization of deep…

Computer Vision and Pattern Recognition · Computer Science 2024-03-28 Ziyu Shan , Yujie Zhang , Qi Yang , Haichen Yang , Yiling Xu , Jenq-Neng Hwang , Xiaozhong Xu , Shan Liu

Photoacoustic imaging (PAI) is a non-invasive imaging modality that detects the ultrasound signal generated from tissue with light excitation. Photoacoustic computed tomography (PACT) uses unfocused large-area light to illuminate the target…

Image and Video Processing · Electrical Eng. & Systems 2022-04-13 Hengrong Lan , Jiali Gong , Fei Gao

Linking a coronagraph instrument to a spectrograph via a single mode optical fiber is a pathway towards detailed characterization of exoplanet atmospheres with current and future ground- and space-based telescopes. However, given the…

The continual push to directly image exoplanets at lower masses and closer separations orbiting around bright stars remains limited by both quasi-static and residual adaptive optics (AO) aberration. In previous papers we have proposed a…

Instrumentation and Methods for Astrophysics · Physics 2020-04-29 Benjamin Gerard , Christian Marois

Model-based reinforcement learning (RL) has proven to be a data efficient approach for learning control tasks but is difficult to utilize in domains with complex observations such as images. In this paper, we present a method for learning…

Machine Learning · Computer Science 2019-06-25 Marvin Zhang , Sharad Vikram , Laura Smith , Pieter Abbeel , Matthew J. Johnson , Sergey Levine

Although acrobatic flight control has been studied extensively, one key limitation of the existing methods is that they are usually restricted to specific maneuver tasks and cannot change flight pattern parameters online. In this work, we…

Robotics · Computer Science 2026-05-18 Zikang Yin , Canlun Zheng , Shiliang Guo , Zhikun Wang , Shiyu Zhao

As reinforcement learning (RL) deployments expand into safety-critical domains, existing evaluation methods fail to systematically identify hazards arising from the black-box nature of neural network enabled policies and distributional…

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