Laurence Denneulin

From linear to nonlinear unfolded condat-vũ algorithm for spectro-polarimetric hight-constrast image recovery

By Édouard Chappon, Nelly Pustelnik, Julian Tachella, Laurence Denneulin, André, Ferrari, Maud Langlois

2024-10-09

In Proceedings of the 32nd european signal processing conference (EUSIPCO 2024)

Abstract

Studying circumstellar environments is crucial for understanding exoplanets and stellar systems. Instruments like SPHERE can extract information about these environments by leveraging advanced image reconstruction methods, possibly based on deep learning. This work focuses on unfolded proximal neural networks based on Condat-Vũ iterations and proposes a new nonlinear formulation. To evaluate and compare the performance of the proposed reconstruction strategies, two datasets dedicated to circumstellar environments analysis in the context of high-contrast imagery have been created offering different level of complexity in the evaluation of the performance.

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An improved spectral extraction method for JWST/NIRSpec fixed slit observations

Abstract

The James Webb Space Telescope is performing beyond our expectations. Its Near Infrared Spectrograph (NIRSpec) provides versatile spectroscopic capabilities in the 0.6-5.3 micrometre wavelength range, where a new window is opening for studying Trans-Neptunian objects in particular. We propose a spectral extraction method for NIRSpec fixed slit observations, with the aim of meeting the superior performance on the instrument with the most advanced data processing. We applied this method on the fixed slit dataset of the guaranteed-time observation program 1231, which targets Plutino 2003 AZ84. We compared the spectra we extracted with those from the calibration pipeline.

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