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The two main advantages of exoplanet imaging are the discovery of objects in the outer part of stellar systems -- constraining models of planet formation --, and its ability to spectrally characterize the planets -- information on their…

Instrumentation and Methods for Astrophysics · Physics 2019-11-13 Raphael Galicher , Pierre Baudoz , Jacques-Robert Delorme , Dimitry Mawet , Mike Bottom , James Kent Wallace , Eugen Serabyn , Chris Sheldon

Reinforcement Learning (RL) has emerged as the key driver for post-training complex reasoning in Large Language Models (LLMs), yet online RL introduces significant instability and computational overhead. Offline RL offers a compelling…

Computation and Language · Computer Science 2026-04-06 Minjae Oh , Yunho Choi , Dongmin Choi , Yohan Jo

Proximal Policy Optimization (PPO) is a highly popular model-free reinforcement learning (RL) approach. However, we observe that in a continuous action space, PPO can prematurely shrink the exploration variance, which leads to slow progress…

Machine Learning · Computer Science 2020-11-04 Perttu Hämäläinen , Amin Babadi , Xiaoxiao Ma , Jaakko Lehtinen

Healthcare data often come from multiple sites in which the correlations between confounding variables can vary widely. If deep learning models exploit these unstable correlations, they might fail catastrophically in unseen sites. Although…

Machine Learning · Computer Science 2023-10-25 Minh Nguyen , Alan Q. Wang , Heejong Kim , Mert R. Sabuncu

Direct imaging of Earth-like planets from space requires dedicated observatories, combining large segmented apertures with instruments and techniques such as coronagraphs, wavefront sensors, and wavefront control in order to reach the high…

The challenges of high contrast imaging (HCI) for detecting exoplanets for both ground and space applications can be met with extreme adaptive optics (ExAO), a high-order adaptive optics system that performs wavefront sensing (WFS) and…

The search for Earth-like exoplanets requires high-contrast and high-angular resolution instruments, which designs can be very complex: they need an adaptive optics system to compensate for the effect of the atmospheric turbulence on image…

Instrumentation and Methods for Astrophysics · Physics 2020-12-16 Lucie Leboulleux , Raphaël Galicher , Eric Gendron , Pierre Baudoz , Gérard Rousset

Context. High-contrast exoplanet imaging is a rapidly growing field as can be seen through the significant resources invested. In fact, the detection and characterization of exoplanets through direct imaging is featured at all major…

Instrumentation and Methods for Astrophysics · Physics 2018-04-17 Markus J. Bonse , Sascha P. Quanz , Adam Amara

Recent advances in photoacoustic (PA) imaging have enabled detailed images of microvascular structure and quantitative measurement of blood oxygenation or perfusion. Standard reconstruction methods for PA imaging are based on solving an…

Signal Processing · Electrical Eng. & Systems 2020-04-17 MinWoo Kim , Geng-Shi Jeng , Ivan Pelivanov , Matthew O'Donnell

In ground-based high-contrast instruments, non-common path aberrations (NCPAs) limit detection performance, as they are unseen by the adaptive optics (AO) wavefront sensor but impact the astrophysical image, creating quasi-static speckles.…

Context. Adaptive optics (AO) is now a tool commonly deployed in astronomy. The real time correction of the atmospheric turbulence that AO enables allows telescopes to perform close to the diffraction limit at the core of their point spread…

Instrumentation and Methods for Astrophysics · Physics 2023-06-21 Anthony Berdeu , Michel Tallon , Éric Thiébaut , Maud Langlois

The discovery of the exoplanet Proxima b highlights the potential for the coming generation of giant segmented mirror telescopes (GSMTs) to characterize terrestrial --- potentially habitable --- planets orbiting nearby stars with direct…

Instrumentation and Methods for Astrophysics · Physics 2017-12-21 Jared R. Males , Olivier Guyon

Optical satellite-to-ground communication (OSGC) has the potential to improve access to fast and affordable Internet in remote regions. Atmospheric turbulence, however, distorts the optical beam, eroding the data rate potential when…

Machine Learning · Computer Science 2023-03-15 Payam Parvizi , Runnan Zou , Colin Bellinger , Ross Cheriton , Davide Spinello

The MEDUSAE method (Multispectral Exoplanet Detection Using Simultaneous Aberration Estimation) is dedicated to the detection of exoplanets and disks features in multispectral high-contrast images. The concept of MEDUSAE is to retrieve both…

Instrumentation and Methods for Astrophysics · Physics 2018-12-12 Faustine Cantalloube , Marie Ygouf , Laurent Mugnier , David Mouillet , Olivier Herscovici-Schiller , Wolfgang Brandner

The exploration of circumstellar environments by means of direct imaging to search for Earth-like exoplanets is one of the challenges of modern astronomy. One of the current limitations are evolving non-common path aberrations (NCPA) that…

Instrumentation and Methods for Astrophysics · Physics 2021-02-24 Steven P. Bos

High contrast coronagraphic imaging of the immediate surrounding of stars requires exquisite control of low-order wavefront aberrations, such as tip-tilt (pointing) and focus. We propose an accurate, efficient and easy to implement…

Instrumentation and Methods for Astrophysics · Physics 2011-02-11 Olivier Guyon , Taro Matsuo , Roger Angel

The search for life via characterization of earth-like planets in the habitable zone is one of the key scientific objectives in Astronomy. We describe a new phase-occulting (PO) interferometric nulling coronagraphy (NC) approach. The PO-NC…

Instrumentation and Methods for Astrophysics · Physics 2015-04-23 Richard G. Lyon , Brian A. Hicks , Mark Clampin , Peter Petrone

Exoplanet research is essential for understanding planetary formation and the potential for life beyond our solar system. The direct imaging method captures exoplanet light while minimizing light from the host star. This is conventionally…

Instrumentation and Methods for Astrophysics · Physics 2025-12-02 Suvinay Goyal , Yinzi Xin , Nemanja Jovanovic , Dimitri Mawet , Michael P. Fitzgerald

This paper demonstrates that continual relearning of control policies using incremental deep reinforcement learning (RL) can improve policy learning for non-stationary processes. We demonstrate this approach for a data-driven 'smart…

Machine Learning · Computer Science 2020-08-06 Avisek Naug , Marcos Quiñones-Grueiro , Gautam Biswas

The raw coronagraphic performance of current high-contrast imaging instruments is limited by the presence of a quasi-static speckle (QSS) background, resulting from instrumental non-common path errors (NCPEs). Rapid development of efficient…

Instrumentation and Methods for Astrophysics · Physics 2017-01-18 Michael J. Wilby , Christoph U. Keller , Frans Snik , Visa Korkiakoski , Alexander G. M. Pietrow
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