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ORBi Open Repository and Bibliography (256.427 recursos)

In may 2007, the ULg's Administrative Board (joined in June 2007 by the FUSAGx) decided to create an institutional repository and defined a strong institutional self-archiving policy to increase the visibility, accessibility and impact of the University's publications (Board's decision). This decision led to the official launch, in November 2008, of the ORBi platform including both the Academic Bibliography and the Institutional Repository of the Wallonia-Europe University Academy.

Engineering, computing & technology => Aerospace & aeronautics engineering

Mostrando recursos 1 - 20 de 928

  1. SWAP and LYRA: space weather from a small spacecraft

    Defise, Jean-Marc; Lecat, Jean-Hervé; Stockman, Yvan; Rochus, Pierre; Mazy, Emmanuel; Denis, François; Halain, Jean-Philippe; Rossi, Laurence; Thibert, Tanguy; Berghmans, D.; others
    Two scientific instruments for Sun observations are being developed to be part of the payload of the ESA's second microsatellite, Proba-II (Project for On-board Autonomy). PROBA-2 is scheduled for launch in early 2007, on a low earth orbit. Like Proba-1, in orbit since October 2001, Proba-2 is a 100-kilogram class spacecraft. PROBA-II will demonstrate new advanced technologies on its scientific payload but also on new platform subsystems such as star tracker, digital Sun sensor, cool gas generator, solar array concentrator, Li-Ion Battery, new central processor, ... This paper is dedicated to the solar payload, comprising the Sun Watcher using Active Pixel...

  2. Straylight tests for the Heliospheric imagers of STEREO

    Defise, Jean-Marc; Halain, Jean-Philippe; Mazy, Emmanuel; Rochus, Pierre
    The design of the Heliospheric Imager (HI) of the NASA Solar TErrestrial Relations Observatory (STEREO) is based on an optical baffle system. It will reject the solar disk light with attenuation of the order of 10-13 and 10-15, and let two separate camera systems (HI-1 and HI-2) measure the extremely faint solar coronal mass ejections. A multi-vane diffractive system has been optimized to achieve the lower requirement (10-13 for HI-1) and is combined with a secondary baffling system to reach the 10-15 rejection performance in the second camera system (HI-2). The theoretical performances of the baffling systems will be experimentally verified...

  3. Design and performances of the heliospheric imager for the STEREO mission

    Mazy, Emmanuel; Halain, Jean-Philippe; Defise, Jean-Marc; Ronchain, Philippe; Howard, Russell A; Moses, J. D.; Eyles, Chris; Harrison, Richard
    The Heliospheric Imager (HI) is part of the SECCHI suite of instruments on-board the two STEREO spacecrafts to be launched in 2006. Located on two different orbits, the two HI instruments will provide stereographic images of solar coronal plasma and coronal mass ejections (CME) over a wide field of view (~90°), ranging from 13 to 330 solar radii (R[SUB]0[/SUB]). These observations complete the 15 R[SUB]0[/SUB] field of view of the solar corona obtained with the other SECCHI instruments (2 coronagraphs and an EUV imager). The HI instrument is a combination of 2 refractive optical systems with 2 different multi-vanes baffle...

  4. MAGRITTE optomechanical design and mirror manufacturing

    Mazy, Emmanuel; Defise, Jean-Marc; Halain, Jean-Philippe; Rochus, Pierre; Rossi, Laurence; Mercier, Raymond; Ravet, Marie-Francoise; Delmotte, Franck; Idir, Mourad
    The MAGRITTE telescopes are part of the SHARPP instrument suite, part of the Solar Dynamics Observatory (SDO), a NASA spacecraft to be launched in a geostationnary orbit in 2007. The MAGRITTE instrument package will provide high resolution images of the solar corona at high temporal frequency simultaneously in 5 EUV and in Ly-alpha narrow bandpasses. The 1.4 R[SUB]0[/SUB] MAGRITTE common field of view complements the other SHARPP instruments, as well as its spectral coverage with 6 narrow bandpasses located within the 19.5 to 120 nm interval. The key challenges of the MAGRITTE instrument are a high angular resolution (0.66 arcsec/pixel)...

  5. The extreme UV imager telescope on-board the Solar Orbiter mission: overview of phase C and D

    Halain, Jean-Philippe; Rochus, Pierre; Renotte, Etienne; Hermans, Aline; Jacques, Lionel; Auchère, Frédéric; Berghmans, David; Harra, Lionel; Schühle, Udo; Schmutz, Werner
    The Solar Orbiter mission is composed of ten scientific instruments dedicated to the observation of the Sun’s atmosphere and its heliosphere, taking advantage of an out-of ecliptic orbit and at perihelion reaching a proximity close to 0.28 A.U. On board Solar Orbiter, the Extreme Ultraviolet Imager (EUI) will provide full-Sun image sequences of the solar corona in the extreme ultraviolet (17.1 nm and 30.4 nm), and high-resolution image sequences of the solar disk in the extreme ultraviolet (17.1 nm) and in the vacuum ultraviolet (121.6 nm). The EUI concept uses heritage from previous similar extreme ultraviolet instrument. Additional constraints from the specific...

  6. Performance of diamond detectors for VUV applications

    BenMoussa, A.; Theissen, A.; Scholze, F.; Hochedez, J. F.; Schühle, U.; Schmutz, W.; Haenen, K.; Stockman, Yvan; Soltani, A.; McMullin, D.; Vest, R. E.; Kroth, U.; Laubis, C.; Richter, M.; Mortet, V.; Gissot, S.; Delouille, V.; Dominique, M.; Koller, S.; Halain, Jean-Philippe; Remes, Z.; Petersen, R.; D'Olieslaeger, M.; Defise, Jean-Marc
    Peer reviewed

  7. The solar orbiter imager (SoloHI) instrument for the Solar Orbiter mission

    Howard, R.; Vourlidas, A.; Korendyke, C.; Plunkett, S.; Carter, T.; Wang, D.; Rich, N.; McMullin, D.; Lynch, Sean; Thurn, Adam; Clifford, G.; Socker, D.; Thernisien, A.; Chua, D.; Linton, M.; Keller, D.; Janesick, J.; Tower, J.; Grygon, M.; Hagood, R.; Bast, W.; Liewer, P.; De Jong, E.; Velli, M.; Mikic, Z.; Bothmer, V.; Rochus, Pierre; Halain, Jean-Philippe; Lamy, P.
    The SoloHI instrument for the ESA/NASA Solar Orbiter mission will track density fluctuations in the inner heliosphere, by observing visible sunlight scattered by electrons in the solar wind. Fluctuations are associated with dynamic events such as coronal mass ejections, but also with the “quiescent” solar wind. SoloHI will provide the crucial link between the low corona observations from the Solar Orbiter instruments and the in-situ measurements on Solar Orbiter and the Solar Probe Plus missions. The instrument is a visible-light telescope, based on the SECCHI/Heliospheric Imager (HI) currently flying on the STEREO mission. In this concept, a series of baffles...

  8. MAGRITTE / SPECTRE : the Solar Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory

    Rochus, Pierre; Defise, Jean-Marc; Halain, Jean-Philippe; Mazy, Emmanuel; Jamar, Claude; Clette, France; Cugnon, P.; Berghmans, D.; Hochedez, J. F.; Delaboudiniere, J. P.; Artzner, G.; Auchere, F.; Mercier, ROSANNA; Ravet, M. F.; Delmotte, Marc; Idir, M.; Fineschi, S.; Antonucci, E.; Harrison, R. A.; Howard, R. A.; Moses, J. D.; Newmark, J. S.
    The Solar Atmospheric Imaging Assembly (AIA) aboard the Solar Dynamics Observatory will characterize the dynamical evolution of the solar plasma from the chromosphere to the corona, and will follow the connection of plasma dynamics with magnetic activity throughout the solar atmosphere. The AIA consists of 7 high resolution imaging telescopes in the following spectral bandpasses: 1215 \x8F Ly-a, 304 \x8F He II, 629 \x8F OV, 465 \x8F Ne VII, 195 \x8F Fe XII (includes Fe XXIV), 284 \x8F Fe XV, and 335 \x8F Fe XVI. The telescopes are grouped by instrumental approach: the Magritte Filtergraphs (R. Magritte, famous 20th Century...

  9. LYRA, a solar UV radiometer on PROBA2

    Hochedez; Schmutz, W.; Stockman, Yvan; Schuhle, U.; BenMoussa, A.; Koller, S.; Haenen, K.; Berghmans, D.; Defise, Jean-Marc; Halain, Jean-Philippe; Theissen, A.; Delouille, V.; Slemzin, V.; Gillotay, D.; Fussen, D.; Dominique, M.; Vanhellemont, F.; McMullin, D.; Kretzschmar, M.; Mitrofanov, A.; Nicula, B.; Wauters, L.; Rochus, Pierre
    Peer reviewed

  10. PROBA II payload: a Belgian mini space weather observatory

    Rochus, Pierre; Defise, Jean-Marc; Lecat, Jean-Hervé; Stockman, Yvan; Franco, P.; Gillis, Jean-Marie; Mazy, Emmanuel; Halain, Jean-Philippe; Rossi, Laurence; Thibert, Tanguy

  11. On-Orbit Degradation of Solar Instruments

    BenMoussa, A.; Gissot, S.; Schühle, U.; Del Zanna, G; Auchère, F.; Mekaoui, S.; Jones, A.R.; Walton, D.; Eyles, C.J.; Thuillier, G.; Seaton, D.; Dammasch, I.E.; Cessateur, G.; Meftah, M.; Andretta, V.; Berghmans, D.; Bewsher, D.; Bolsee, D.; Bradley, L.; Brown, D.S.; Chamberlin, P.C.; Dewitte, S.; Didkovsky, L.V.; Dominique, M.; Eparvier, F.G.; Foujols, T.; Gillotay, D.; Giordanengo, B.; Halain, Jean-Philippe; Hock, R.A.; Irbah, A.; Jeppesen, C.; Judge, D.L.; Kretzschmar, M.; McMullin, D.R.; Nicula, B.; Schmutz, W.; Ucker, G.; Wieman, S.; Woodraska, D.; Woods, T.N.
    Peer reviewed

  12. The solar and heliospheric imager (SoloHI) instrument for the solar orbiter mission

    Howard, R. A.; Vourlidas, A.; Korendyke, C. M.; Plunkett, S. P.; Carter, M. T.; Wang, Da; Rich, N.; McMullin, D. R.; Lynch, S.; Thurn, A.; Clifford, G.; Socker, D. G.; Thernisien, A. F.; Chua, D.; Linton, M. G.; Keller, D.; Janesick, J. R.; Tower, J.; Grygon, M.; Hagood, R.; Bast, W.; Liewer, P. C.; DeJong, E. M.; Velli, M. M. C.; Mikic, Z.; Bothmer, V.; Rochus, Pierre; Halain, Jean-Philippe; Lamy, P. L.
    The SoloHI instrument for the ESA/NASA Solar Orbiter mission will track density fluctuations in the inner heliosphere, by observing visible sunlight scattered by electrons in the solar wind. Fluctuations are associated with dynamic events such as coronal mass ejections, but also with the “quiescent” solar wind. SoloHI will provide the crucial link between the low corona observations from the Solar Orbiter instruments and the in-situ measurements on Solar Orbiter and the Solar Probe Plus missions. The instrument is a visible-light telescope, based on the SECCHI/Heliospheric Imager (HI) currently flying on the STEREO mission. In this concept, a series of baffles...

  13. Identification of nonlinear frequency responses and bifurcations from experimental data

    Noël, Jean-Philippe; Gourc, Etienne; Grappasonni, Chiara; Detroux, Thibaut; Kerschen, Gaëtan
    The objective of the paper is to obtain the frequency response curves of nonlinear mechanical systems from broadband testing. The proposed approach consists in coupling an identification method with a continuation method. Specifically, the frequency-domain nonlinear subspace identification (FNSI) method is first used to derive an experimental model of the structure in state-space from broadband measurements. The harmonic balance method coupled with arclength continuation then utilizes this experimental model to compute the frequency response curves of the system. The method is demonstrated using a numerical example.

  14. Finite Element Model Reduction for Spacecraft Thermal Analysis

    Jacques, Lionel; Masset, Luc; Kerschen, Gaëtan
    The finite element method (FEM) is widely used in mechanical engineering, especially for space structure design. However, FEM is not yet often used for thermal engineering of space structures where the lumped parameter method (LPM) is still dominant. Both methods offer advantages and disadvantages and the proposed global approach tries to combine both methods: - The LPM conductive links are error-prone and still too often computed by hand. This is incompatible with the increasing accuracy required by the thermal control systems (TCS) and associated thermal models. Besides offering the automatic and accurate computation of the conductive links, the FEM also provides easy...

  15. Numerical Modeling and Experimental Identification of Mistuned Multi-Stage Bladed Assemblies

    Nyssen, Florence
    In turbomachinery, low pressure compressors are composed of a succession of bladed disks. To reduce the mass and increase the performance of the aircraft engines, one-piece multi-stage units of bladed disks have been recently developed. But these one-piece technologies are challenging for the mechanical design due to exacerbated effects of mistuning (i.e., mode localization and forced response amplification). In the thesis, an experimental method for the identification of mistuning in multi-stage bladed structures is proposed and validated. Numerical modeling methods are proposed to reduce computational times for the statistical predictions of the forced response amplification. A characterization of the interstage...

  16. The IMAGE Mission (NASA): design, test and results from the Far UV Spectrographic Imaging

    Habraken, Serge; Renotte, Etienne; Rochus, Pierre; Defise, Jean-Marc; Jamar, Claude; Gérard, Jean-Claude; Hubert, Benoît; Meurant, Matthieu; Munhoven, Serge
    Peer reviewed

  17. ISU team project: Space debris mitigation and removal

    Adriaensen, Maarten; Rüdiger, Jehn; Gini, Andrea; Faure, Pauline; Datta, Iman; Fournier, Paul; Hilbich, Daniel; Jacques, Lionel; Maier, Philipp; Mukherjee, Bulbul; Seymour, Mark; Shahverdyan, Tigran; Shioi, Hiroaki; Sinn, Thomas; Torelli, Felice
    Peer reviewed

  18. Grey-box nonlinear state-space modelling for mechanical vibrations identification

    Noël, Jean-Philippe; Schoukens, Johan; Kerschen, Gaëtan
    Peer reviewed

  19. A nonlinear state-space solution to a hysteretic benchmark in system identification

    Noël, Jean-Philippe; Esfahani, Alireza; Kerschen, Gaëtan; Schoukens, Johan

  20. Challenging ourselves: three benchmarks for nonlinear system identification

    Schoukens, Maarten; Noël, Jean-Philippe

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