Dr. Jean-Hervé M. Lecat Profile

Dr. Jean-Hervé M. Lecat

at Liège Univ

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Author

Publications (10)

Proceedings Article | 13 April 2018 Paper

SWAP: Sun watcher with a new EUV telescope on a technology demonstration platform

Jean-Marc Defise, Jean-Hervé Lecat, Emmanuel Mazy, Pierre Rochus, Laurence Rossi, Tanguy Thibert, Jean-Marie Gillis, David Berghmans, Jean-Francois Hochedez, Udo Schühle

Proceedings Volume 10568, 1056825 (2018) https://doi.org/10.1117/12.2500100

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SWAP (SWAP (Sun Watcher using Active Pixel System detector and Image Processing) is an instrument that has been selected to fly on the PROBA- 2 technology demonstration platform, a program of the European Space Agency (ESA) to be launched in 2006. SWAP is based on an off-axis degraded Ritchey Chretien telescope that will image the EUV solar corona at 19.5 nm on a specifically fabricated extreme ultraviolet (EUV) sensitivity enhanced CMOS APS detector. The optical design and the optical coatings are derived from the Extreme Ultraviolet Imaging Telescope (EIT) operating on-board SOHO since 1995 [1]. It has been adapted for a single wavelength telescope with off-axis optics. It allows to use smaller optics and filters, with simple internal baffles avoiding external protruding parts. The superpolished optics will receive a multilayer coating that provides spectral selection centred on 19.5 nm and EUV reflectivity in normal incidence. This compact design is specifically adapted for accommodation on PROBA-2, where mass and envelope requirements are very stringent The SWAP PROBA-2 program will be an opportunity to demonstrate this new optical concept, while it will also validate space remote sensing with APS detectors, as well as on-board image processing capabilities. On the science outcomes, SWAP will provide solar corona images in the Fe XII line on a baselined 2-min cadence. Observations with this specific wavelength allow detecting phenomena, such as solar flares or ‘EIT-waves’, associated with the early phase of coronal mass ejections. The SWAP data will complement the observations provided by SOHO-EIT, and STEREOSECCHI. is an instrument that has been selected to fly on the PROBA- 2 technology demonstration platform, a program of the European Space Agency (ESA) to be launched in 2006. SWAP is based on an off-axis degraded Ritchey Chretien telescope that will image the EUV solar corona at 19.5 nm on a specifically fabricated extreme ultraviolet (EUV) sensitivity enhanced CMOS APS detector. The optical design and the optical coatings are derived from the Extreme Ultraviolet Imaging Telescope (EIT) operating on-board SOHO since 1995 [1]. It has been adapted for a single wavelength telescope with off-axis optics. It allows to use smaller optics and filters, with simple internal baffles avoiding external protruding parts. The superpolished optics will receive a multilayer coating that provides spectral selection centred on 19.5 nm and EUV reflectivity in normal incidence. This compact design is specifically adapted for accommodation on PROBA-2, where mass and envelope requirements are very stringent The SWAP PROBA-2 program will be an opportunity to demonstrate this new optical concept, while it will also validate space remote sensing with APS detectors, as well as on-board image processing capabilities. On the science outcomes, SWAP will provide solar corona images in the Fe XII line on a baselined 2-min cadence. Observations with this specific wavelength allow detecting phenomena, such as solar flares or ‘EIT-waves’, associated with the early phase of coronal mass ejections. The SWAP data will complement the observations provided by SOHO-EIT, and STEREOSECCHI.

Proceedings Article | 21 November 2017 Open Access

An interferometer for high-resolution optical surveillance from geostationary orbit

L. Bonino, F. Bresciani, G. Piasini, C. Flebus, J.-H. Lecat, S. Roose, M. Pisani, A. Cabral, J. Rebordão, C. Proença, J. Costal, P. Lima, N. Loix, F. Musso

Proceedings Volume 10567, 1056708 (2017) https://doi.org/10.1117/12.2308170

KEYWORDS: Space telescopes, Telescopes, Interferometers, Sensors, Mirrors, Metrology, Surveillance, Optics manufacturing, Infrared telescopes, Point spread functions

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Proceedings Article | 21 November 2017 Open Access

An interferometer for high-resolution optical surveillance from geostationary orbit - space system study

L. Bonino, F. Bresciani, G. Piasini, C. Flebus, J.-H. Lecat, S. Roose, M. Pisani, A. Cabral, J. Rebordão, C. Proença, J. Costal, P. Lima, F. Musso

Proceedings Volume 10567, 1056733 (2017) https://doi.org/10.1117/12.2308169

KEYWORDS: Interferometers, Sensors, Space telescopes, Telescopes, Metrology, Point spread functions, Mirrors, Surveillance, Modulation transfer functions, Control systems design

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Proceedings Article | 21 November 2017 Open Access

Synthetic aperture co-phasing and co-alignment using an external reference source

Stéphane Roose, Jean-Christophe Bolsee, Jean-Hervé Lecat, Nicolas Loix

Proceedings Volume 10567, 105670A (2017) https://doi.org/10.1117/12.2308074

KEYWORDS: Sensors, Fourier transforms, Phase shifting, Point spread functions, Calibration, Telescopes, Space telescopes, Phase measurement, Phase shifts, Astronomical imaging

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Proceedings Article | 15 May 2014 Paper

Investigation of spectral impacts on the performance of a concentration device using a Fresnel lens combined with a double junction cell

Jérôme Loicq, Nicolas Galante, Tanguy Thibert, Marie-Laure Hellin, F. Languy, S. Habraken, Jean-Hervé Lecat

Proceedings Volume 9140, 91400T (2014) https://doi.org/10.1117/12.2051672

KEYWORDS: Fresnel lenses, Chromatic aberrations, Colorimetry, Solar cells, Photovoltaics, Solar concentrators, Lens design, Geometrical optics, Optical components, Sun

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Proceedings Article | 20 September 2007 Paper

SWAP: a novel EUV telescope for space weather

Jean-Marc Defise, Jean-Philippe Halain, David Berghmans, François Denis, Emmanuel Mazy, Tanguy Thibert, Jean-Hervé Lecat, Pierre Rochus, Bogdan Nicula, Anik De Groof, Jean-François Hochedez, Udo Schühle, Marie-Françoise Ravet, Frank Delmotte

Proceedings Volume 6689, 66890S (2007) https://doi.org/10.1117/12.731784

KEYWORDS: Extreme ultraviolet, Mirrors, Space telescopes, Sensors, Telescopes, Electronics, Space operations, Thermal modeling, Multilayers, Sun

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Proceedings Article | 18 August 2005 Paper

SWAP: an EUV imager for solar monitoring on board of PROBA2

Athanassios Katsiyannis, David Berghmans, Jean-Francois Hochedez, Bogdan Nicula, Gareth Lawrence, Jean-Marc Defise, Ali Ben-Moussa, Veronique Delouille, Marie Dominique, Jean-Herve Lecat, W. Schmutz, Armin Theissen, Vladimir Slemzin

Proceedings Volume 5901, 59010V (2005) https://doi.org/10.1117/12.616803

KEYWORDS: Sensors, Solar processes, Extreme ultraviolet, Sun, Curium, Space operations, Satellites, Vacuum ultraviolet, Iron, Coronagraphy

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Proceedings Article | 26 February 2004 Paper

Development of an infrared collimator as optical ground support equipment for IASI instrument

Jean-Herve Lecat, Philippe Ronchain, Pierre Franco, Yvette Houbrechts, Emmanuel Mazy, Yvan Stockman, Pierre Gloesener, Philippe Cheroutre

Proceedings Volume 5252, (2004) https://doi.org/10.1117/12.512310

KEYWORDS: Collimators, Black bodies, Infrared radiation, Sensors, Optics manufacturing, Imaging systems, Mirrors, Optical filters, Temperature metrology, Contamination

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Proceedings Article | 4 February 2004 Paper

SWAP: Sun watcher using APS detector on-board PROBA-2, a new EUV off-axis telescope on a technology demonstration platform

Jean-Marc Defise, David Berghmans, Jean-Francois Hochedez, Jean-Herve Lecat, Emmanuel Mazy, Pierre Rochus, Tanguy Thibert, Piergiorgio Nicolosi, Maria Pelizzo, Udo Schuehle, Ronald Van der Linden, Andrei Zhukov

Proceedings Volume 5171, (2004) https://doi.org/10.1117/12.516510

KEYWORDS: Sensors, Mirrors, Extreme ultraviolet, Space telescopes, Multilayers, Solar processes, Telescopes, Sun, Reflectivity, Coronagraphy

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Proceedings Article | 1 November 1996 Paper

Characterization of the holographic imaging grating of GOMOS UVIS spectrometer

Jussi Graeffe, Heikki Saari, Heikki Astola, Kari Rainio, Lorand Mazuray, Dominique Pierot, Pierre Craen, Michel Gruslin, Jean-Herve Lecat, Francis Bonnemason, Jean Flamand, Alain Thevenon

Proceedings Volume 2863, (1996) https://doi.org/10.1117/12.256220

KEYWORDS: Holography, Sensors, Spectroscopy, Interfaces, Diffraction gratings, Imaging systems, Monochromatic aberrations, Optical design, Charge-coupled devices, Manufacturing

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