Mr. Fabien A. Dupont Profile

Fabien A. Dupont

Systems Engineer at Telops

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Author

Publications (7)

Proceedings Article | 11 January 2018 Open Access

Alignment monitoring system for ASTRO-H

Frédéric Grandmont, Fabien Dupont, Louis Moreau, Martin Larouche, Louis-Philippe Bibeau, Sylvio Laplante

Proceedings Volume 10565, 1056557 (2018) https://doi.org/10.1117/12.2309127

KEYWORDS: Sensors, X-rays, Imaging systems, Optical benches, Amplitude modulation, X-ray optics, Hard x-rays, Astronomical imaging, Observatories, X-ray imaging

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High Energy Astrophysics (HEA) encompasses a broad range of astrophysical science, with sources that include stars and stellar clusters, compact objects (black holes, neutron stars, and white dwarfs), supernova remnants, the interstellar medium, galaxies and clusters of galaxies, Active Galactic Nuclei (AGN), and gamma ray bursters, as well as a variety of fundamental physical processes. The physics involved includes extremes of gravity, density and magnetic field and is often inaccessible via any other waveband. HEA investigates and answers crucial questions in all fields of contemporary astrophysics.

Unlike the focusing of radio and optical light, X-rays are brought to focus through shallow, grazing incident angles. The analogy of skimming a stone across a pond is appropriate in describing how X-rays are focused. The higher the energy of the X-ray photon the shallower the incident angle must be, thereby introducing the requirement of longer focal lengths for focusing high-energy X-rays (E > 10 keV). This technical challenge has hindered scientific advancement in the high-energy regime, while at lower X-ray energies the community has prospered immensely with spectacular data from focusing observatories like XMM-Newton, Chandra, and Suzaku. Now, with ASTRO-H, the community will reap similar rewards from the tremendous improvement in spatial and spectral resolution at high energies. ASTRO-H is a JAXA mission. More information can be found on the ASTRO-H web site [1].

Because of the grazing-angle optics, high-energy X-ray instruments have a long focal length. The Hard X-ray Imager (HXI) of ASTRO-H has its detector housed in a boom that will extend by about 6 m in orbit so that a focal length of 12 m can be achieved for that instrument. This long structure will inevitably oscillate and flex, especially when passing across the orbital day/night boundary. In order to retain the essential imaging resolution, it is important that the boom has a metrology system that measures this flexion in order to allow post-acquisition compensation in generating the science images. In the current paper, we describe a possible Alignment Monitoring System (AMS) to measure in real time the relative position of the boom. The AMS will be an important element to guaranty that the ASTRO-H observatory will meet its performance requirements.

The Canadian Space Agency has the intention of providing the AMS to the ASTRO-H mission. The current paper reports a study that was conducted to support that intention.

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Proceedings Article | 17 November 2017 Open Access

HVRM: a second generation ACE-FTS instrument concept

Jean-François Lavigne, Martin Larouche, Fabien Dupont, Guillaume Girard, James Veilleux, Henry Buijs, Raphaël Desbiens, Gaétan Perron, Frédéric Grandmont, Simon Paradis, Louis Moreau, Hugo Bourque

Proceedings Volume 10563, 1056345 (2017) https://doi.org/10.1117/12.2304247

KEYWORDS: Sun, Mirrors, Clouds, Sensors, Astronomical imaging, Interferometers, Image filtering, Imaging systems, Finite element methods, Earth's atmosphere

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The Atmospheric Chemistry Experiment Fourier Transform Spectrometer (ACE-FTS) is the main instrument on-board the SCISAT-1 satellite, a mission mainly supported by the Canadian Space Agency [1]. It is in Low- Earth Orbit at an altitude of 650 km with an inclination of 74E. Its data has been used to track the vertical profile of more than 30 atmospheric species in the high troposphere and in the stratosphere with the main goal of providing crucial information for the comprehension of chemical and physical processes controlling the ozone life cycle. These atmospheric species are detected using high-resolution (0.02 cm^-1) spectra in the 750-4400 cm^-1 spectral region. This leads to more than 170 000 spectral channels being acquired in the IR every two seconds. It also measures aerosols and clouds to reduce the uncertainty in their effects on the global energy balance. It is currently the only instrument providing such in-orbit high resolution measurements of the atmospheric chemistry and is often used by international scientists as a unique data set for climate understanding.

The satellite is in operation since 2003, exceeding its initially planned lifetime of 2 years by more than a factor of 5. Given its success, its usefulness and the uniqueness of the data it provides, the Canadian Space Agency has founded the development of technologies enabling the second generation of ACE-FTS instruments through the High Vertical Resolution Measurement (HVRM) project but is still waiting for the funding for a mission.

This project addresses three major improvements over the ACE-FTS. The first one aims at improving the vertical instantaneous field-of-view (iFoV) from 4.0 km to 1.5 km without affecting the SNR and temporal precision. The second aims at providing precise knowledge on the tangent height of the limb observation from an external method instead of that used in SCISAT-1 where the altitude is typically inferred from the monotonic CO2 concentration seen in the spectra. The last item pertains to reaching lower altitude down to 5 km for the retrieved gas species, an altitude at which the spectra are very crowded in terms of absorption. These objectives are attained through a series of modification in the optical train such as the inclusion of a field converter and a series of dedicated real-time and post-acquisition algorithms processing the Sun images as it hides behind the Earth. This paper presents the concepts, the prototypes that were made, their tests and the results obtained in this Technology Readiness Level (TRL) improvement project.

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Proceedings Article | 19 October 2012 Paper

CARVE-FTS observations of arctic CO2, CH4, and CO: overview of the instrument

Fabien Dupont, François Tanguay, Manyuan Li, Gaetan Perron, Charles Miller, Steven Dinardo, Thomas Kurosu

Proceedings Volume 8532, 853204 (2012) https://doi.org/10.1117/12.979826

KEYWORDS: Signal to noise ratio, Polarization, Sensors, Fourier transforms, Modulators, Carbon dioxide, Carbon monoxide, Interferometers, Black bodies, Carbon

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Proceedings Article | 27 April 2010 Paper

A microbolometer-based THz imager

Linda Marchese, Martin Bolduc, Bruno Tremblay, Michel Doucet, Hassane Oulachgar, Loïc Le Noc, Fraser Williamson, Christine Alain, Hubert Jerominek, Alain Bergeron

Proceedings Volume 7671, 76710Z (2010) https://doi.org/10.1117/12.850723

KEYWORDS: Terahertz radiation, Cameras, Imaging systems, Quantum cascade lasers, Staring arrays, Indium oxide, Microbolometers, Sensors, Video, Objectives

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Proceedings Article | 7 May 2009 Paper

Space qualification of a 512x3 pixel uncooled microbolometer FPA

Timothy Pope, Fabien Dupont, Sonia Garcia Blanco, Fraser Williamson, Claude Chevalier, Linda Marchese, Francois Chateauneuf, Hubert Jerominek, Ngo-Phong Linh, Robert Bouchard

Proceedings Volume 7298, 729826 (2009) https://doi.org/10.1117/12.819922

KEYWORDS: Staring arrays, Sensors, Temperature metrology, Long wavelength infrared, Microbolometers, Cameras, Mid-IR, Radio optics, Stray light, Black bodies

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Proceedings Article | 1 May 2009 Paper

Uncooled detector, optics, and camera development for THz imaging

Timothy Pope, Michel Doucet, Fabien Dupont, Linda Marchese, Bruno Tremblay, Georges Baldenberger, Sonia Verrault, Frédéric Lamontagne

Proceedings Volume 7311, 73110L (2009) https://doi.org/10.1117/12.819923

KEYWORDS: Terahertz radiation, Sensors, Cameras, Silicon, Absorption, Staring arrays, Indium oxide, Tolerancing, Modulation transfer functions, Antireflective coatings

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Proceedings Article | 24 February 2009 Paper

Advanced microbolometer detectors for a next-generation uncooled FPA for space-based thermal remote sensing

Fraser Williamson, Linda Marchese, Georges Baldenberger, François Châteauneuf, Francis Provencal, Jean-Sol Caron, Fabien Dupont, Jocelyne Osouf, Patrick Couture, Linh Ngo Phong, Tim Pope

Proceedings Volume 7208, 72080J (2009) https://doi.org/10.1117/12.810026

KEYWORDS: Sensors, Microbolometers, Staring arrays, Long wavelength infrared, Clouds, Readout integrated circuits, Sensor performance, Thermal remote sensing, Detector development, Mid-IR

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Showing 5 of 7 publications

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