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Most of the high-contrast imaging (HCI) data-processing techniques used over the last 15 years have relied on the angular differential imaging (ADI) observing strategy, along with subtraction of a reference point spread function (PSF) to…

Instrumentation and Methods for Astrophysics · Physics 2021-12-08 Carl-Henrik Dahlqvist , Faustine Cantalloube , Olivier Absil

Most current high contrast imaging point spread function (PSF) subtraction algorithms use some form of a least-squares noise minimization to find exoplanets that are, before post-processing, often hidden below the instrumental speckle…

Instrumentation and Methods for Astrophysics · Physics 2016-09-29 Benjamin L. Gerard , Christian Marois

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

Direct imaging of exoplanets is usually limited by quasi-static speckles. These uncorrected aberrations in a star's point spread function (PSF) obscure faint companions and limit the sensitivity of high-contrast imaging instruments. Most…

Instrumentation and Methods for Astrophysics · Physics 2021-05-05 William Thompson , Christian Marois

We propose a direct imaging method for the detection of exoplanets based on a combined low-rank plus structured sparse model. For this task, we develop a dictionary of possible effective circular trajectories a planet can take during the…

Instrumentation and Methods for Astrophysics · Physics 2023-01-18 Simon Vary , Hazan Daglayan , Laurent Jacques , Pierre-Antoine Absil

We propose to use low-rank matrix approximation using the component-wise L1-norm for direct imaging of exoplanets. Exoplanet detection by direct imaging is a challenging task for three main reasons: (1) the host star is several orders of…

Instrumentation and Methods for Astrophysics · Physics 2023-10-30 Hazan Daglayan , Simon Vary , Valentin Leplat , Nicolas Gillis , P. -A. Absil

Direct imaging of exoplanets is limited by bright quasi-static speckles in the point spread function (PSF) of the central star. This limitation can be reduced by subtraction of reference PSF images. We have developed an algorithm to…

Astrophysics · Physics 2011-02-11 David Lafreniere , Christian Marois , Rene Doyon , Daniel Nadeau , Etienne Artigau

Beyond the choice of wavefront control systems or coronographs, advanced data processing methods play a crucial role in disentangling potential planetary signals from bright quasi-static speckles. Among these methods, angular differential…

Instrumentation and Methods for Astrophysics · Physics 2020-01-22 Carl-Henrik Dahlqvist , Faustine Cantalloube , Olivier Absil

Direct imaging of exoplanets is a challenging task due to the small angular distance and high contrast relative to their host star, and the presence of quasi-static noise. We propose a new statistical method for direct imaging of exoplanets…

Instrumentation and Methods for Astrophysics · Physics 2022-10-20 Hazan Daglayan , Simon Vary , Faustine Cantalloube , P. -A. Absil , Olivier Absil

The combination of high-contrast imaging and medium to high spectral resolution spectroscopy offers new possibilities for the detection and characterization of exoplanets. The molecular mapping technique uses the difference between the…

Instrumentation and Methods for Astrophysics · Physics 2023-11-23 Alexis Bidot , David Mouillet , Alexis Carlotti

Digital co-addition of astronomical images is a common technique for increasing signal-to-noise and image depth. A modification of this simple technique has been applied to the detection of minor bodies in the Solar System: first stationary…

Earth and Planetary Astrophysics · Physics 2015-05-18 Alex H. Parker , JJ. Kavelaars

The recovery of images from the observations that are degraded by a linear operator and further corrupted by Poisson noise is an important task in modern imaging applications such as astronomical and biomedical ones. Gradient-based…

Computer Vision and Pattern Recognition · Computer Science 2015-03-17 Dai-Qiang Chen

We propose a globally convergent alternating minimization (AM) algorithm for image reconstruction in transmission tomography, which extends automatic relevance determination (ARD) to Poisson noise models with Beer's law. The algorithm…

We present additional tests of our algorithm aimed at filtering out systematics due to data reduction and instrumental imperfections in time series obtained by ensemble photometry. Signal detection efficiency is demonstrated, and a method…

Astrophysics · Physics 2007-05-23 G. Kovacs , G. A. Bakos

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

The alternating minimization (AM) method is a fundamental method for minimizing convex functions whose variable consists of two blocks. How to efficiently solve each subproblems when applying the AM method is the most concerned task. In…

Optimization and Control · Mathematics 2015-01-16 Hui Zhang , Lizhi Cheng

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

To directly image exoplanets and faint circumstellar disks, the noisy stellar halo must be suppressed to a high level. To achieve this feat, the angular differential imaging observing technique and the least-squares Locally Optimized…

Instrumentation and Methods for Astrophysics · Physics 2015-06-22 Christian Marois , Carlos Correia , Raphael Galicher , Patrick Ingraham , Bruce Macintosh , Thayne Currie , Rob De Rosa

Low-rank plus diagonal (LRPD) decompositions provide a powerful structural model for large covariance matrices, simultaneously capturing global shared factors and localized corrections that arise in covariance estimation, factor analysis,…

Numerical Analysis · Mathematics 2025-12-22 Kingsley Yeon , Mihai Anitescu

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
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