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18 results on '"Meftah, A."'

1. A New Version of the SOLAR-ISS Spectrum Covering the 165 – 3000 nm Spectral Region

Author

Meftah, M., primary, Damé, L., additional, Bolsée, D., additional, Pereira, N., additional, Snow, M., additional, Weber, M., additional, Bramstedt, K., additional, Hilbig, T., additional, Cessateur, G., additional, Boudjella, M.-Y., additional, Marchand, M., additional, Lefèvre, F., additional, Thiéblemont, R., additional, Sarkissian, A., additional, Hauchecorne, A., additional, Keckhut, P., additional, and Bekki, S., additional

Published
2020
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2. The New SCIAMACHY Reference Solar Spectral Irradiance and Its Validation

Author

Hilbig, T., primary, Weber, M., additional, Bramstedt, K., additional, Noël, S., additional, Burrows, J. P., additional, Krijger, J. M., additional, Snel, R., additional, Meftah, M., additional, Damé, L., additional, Bekki, S., additional, Bolsée, D., additional, Pereira, N., additional, and Sluse, D., additional

Published
2018
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3. SOVAP/Picard, a Spaceborne Radiometer to Measure the Total Solar Irradiance

Author

M. Meftah, S. Dewitte, A. Irbah, A. Chevalier, C. Conscience, D. Crommelynck, E. Janssen, S. Mekaoui, STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Royal Météorologique de Belgique [Bruxelles] (IRM), and Institut Royal Météorologique de Belgique [Bruxelles] - Royal Meteorological Institute (IRM)

Subjects
Physics, Radiometer, Meteorology, Spacecraft, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], business.industry, Payload, [SDE.MCG]Environmental Sciences/Global Changes, Solar Irradiance, Measure (physics), Astronomy and Astrophysics, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Solar irradiance, 7. Clean energy, Instrumental Effects, Amplitude, [SDU.STU.CL]Sciences of the Universe [physics]/Earth Sciences/Climatology, 13. Climate action, Space and Planetary Science, Orbit (dynamics), Solar Cycle Observations, Instrumentation and Data Management, business, Solar variation, Remote sensing
Abstract

International audience; The Picard spacecraft was successfully launched on June 15, 2010, into a Sun synchronous orbit. The mission represents one of the European contributions to solar observations and Essential Climate Variables (ECVs) measurements. The payload is composed of a Solar Diameter Imager and Surface Mapper (SODISM) and two radiometers: SOlar VAriability Picard (SOVAP) and PREcision MOnitor Sensor (PREMOS). SOVAP, a dual side-by-side cavity radiometer, measures the total solar irradiance (TSI). It is the sixth of a series of differential absolute radiometer type instruments developed and operated in space by the Royal Meteorological Institute of Belgium. The measurements of SOVAP in the summer of 2010, yielded a TSI value of 1362.1 W.m−2 with an uncertainty of ±2.4W.m−2 (k=1). During the periods of November 2010 and January 2013, the amplitude of the changes in TSI has been of the order of 0.18%, corresponding to a range of about 2.4W.m−2.

Published
2013
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4. The Plate Scale of the SODISM Instrument and the Determination of the Solar Radius at 607.1 nm

Author

Djelloul Djafer, Jean-François Hochedez, Mickael Crepel, Mustapha Meftah, Thierry Corbard, Alain Hauchecorne, Abdanour Irbah, STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Observatoire de la Côte d'Azur (OCA), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Unité de Recherche Appliquée en Energies Renouvelables (URAER), and Ministère de l'Enseignement Supérieur et de la Recherche Scientifique [Algérie] (MESRS)

Subjects
Physics, Scale (ratio), Spacecraft, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], business.industry, Center-limb observations, Astrophysics::Instrumentation and Methods for Astrophysics, Instrumental effects, Astronomy and Astrophysics, Solar radius, Solar diameter, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], law.invention, Metrology, Telescope, Optics, Space and Planetary Science, law, Physics::Space Physics, Calibration, Astrophysics::Earth and Planetary Astrophysics, Transit (astronomy), business, Instrumentation and data management, Space environment
Abstract

International audience; Knowledge of the Solar Diameter Imager and Surface Mapper (SODISM) plate scale is a fundamental parameter for obtaining the solar radius. We have determined the plate scale of the telescope on the ground and in flight onboard the Picard spacecraft. The results show significant differences; the main reason is that the conditions of observation are not the same. In addition, the space environment has an impact on the performance of a metrology instrument. Therefore, calibration in space and under the same conditions of observation is crucial. The transit of Venus allowed us to determine the plate scale of the SODISM telescope and hence the absolute value of the solar radius. The transit was observed from space by the Picard spacecraft on 5 - 6 June 2012. We exploited the data recorded by SODISM to determine the plate scale of the instrument, which depends on the characteristics of optical elements (mirrors, filters, or front window). The mean plate scale at 607.1 nm is found to be 1.0643 arcseconds pixel−1 with 3×10−4 RMS. The solar radius at 607.1 nm from 1 AU is found to be equal to 959.86 arcseconds.

Published
2013
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5. On-Orbit Degradation of Solar Instruments

Author

Vincenzo Andretta, Udo Schühle, D. Walton, C. Jeppesen, L. Bradley, Matthieu Kretzschmar, M. Dominique, Abdanour Irbah, Andrew R. Jones, Thomas N. Woods, B. Giordanengo, C. J. Eyles, Werner Schmutz, G. Del Zanna, Gregory J. Ucker, Frédéric Auchère, Francis G. Eparvier, Daniel B. Seaton, Daniel Stephen Brown, Leonid Didkovsky, Don Woodraska, Seth Wieman, Darrell L. Judge, Jean-Philippe Halain, David Berghmans, Mustapha Meftah, Thomas Foujols, S. Mekaoui, Gaël Cessateur, G. Thuillier, Steven Dewitte, I. E. Dammasch, Rachel Hock, D. Gillotay, B. Nicula, Phillip C. Chamberlin, Samuel Gissot, Ali BenMoussa, David Bolsee, Danielle Bewsher, D. R. McMullin, Solar-Terrestrial Centre of Excellence [Brussels] (STCE), Royal Observatory of Belgium [Brussels] (ROB), Max-Planck-Institut für Sonnensystemforschung (MPS), Max-Planck-Gesellschaft, Department of Applied Mathematics and Theoretical Physics (DAMTP), University of Cambridge [UK] (CAM), Institut d'astrophysique spatiale (IAS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Institut Royal Météorologique de Belgique [Bruxelles] (IRM), European Commission - Joint Research Centre [Ispra] (JRC), Laboratory for Atmospheric and Space Physics [Boulder] (LASP), University of Colorado [Boulder], Mullard Space Science Laboratory (MSSL), University College of London [London] (UCL), Grupo de Astronomia y Ciencias del Espacio (GACE), Laboratorio de Procesado de Imagenes [Valencia] (LPI), Universitat de València (UV)-Universitat de València (UV), Space Science and Technology Department [Didcot] (RAL Space), STFC Rutherford Appleton Laboratory (RAL), Science and Technology Facilities Council (STFC)-Science and Technology Facilities Council (STFC), STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), INAF - Osservatorio Astronomico di Capodimonte (OAC), Istituto Nazionale di Astrofisica (INAF), Jeremiah Horrocks Institute for Mathematics, Physics and Astronomy [Preston], University of Central Lancashire [Preston] (UCLAN), Belgian Institute for Space Aeronomy / Institut d'Aéronomie Spatiale de Belgique (BIRA-IASB), NASA Goddard Space Flight Center (GSFC), University of Southern California (USC), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Centre Spatial de Liège (CSL), Université de Liège, Air Force Research Laboratory (AFRL), United States Air Force (USAF), Laboratoire de Physique et Chimie de l'Environnement et de l'Espace (LPC2E), Observatoire des Sciences de l'Univers en région Centre (OSUC), Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université d'Orléans (UO)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National d’Études Spatiales [Paris] (CNES), Space Systems Research Corporation (SSRC), Physikalisch-Meteorologisches Observatorium Davos/World Radiation Center (PMOD/WRC), Max-Planck-Institut für Sonnensystemforschung = Max Planck Institute for Solar System Research (MPS), Université Paris-Sud - Paris 11 (UP11)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES), Institut Royal Météorologique de Belgique [Bruxelles] - Royal Meteorological Institute (IRM), Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences de l'Univers (INSU - CNRS)-Observatoire de Paris, and Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Université d'Orléans (UO)-Centre National de la Recherche Scientifique (CNRS)-Centre National d’Études Spatiales [Paris] (CNES)

Subjects
solar instruments, [PHYS.ASTR.IM]Physics [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], 010504 meteorology & atmospheric sciences, FOS: Physical sciences, Solar mission, Space weather, Space (commercial competition), 7. Clean energy, 01 natural sciences, Space exploration, Degradation, Contamination, Observatory, 0103 physical sciences, Aerospace engineering, Instrumentation and Methods for Astrophysics (astro-ph.IM), 010303 astronomy & astrophysics, Solar and Stellar Astrophysics (astro-ph.SR), 0105 earth and related environmental sciences, business.industry, Astronomy and Astrophysics, con- tamination, calibration, space environment, [SDU.ASTR.IM]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Instrumentation and Methods for Astrophysic [astro-ph.IM], Astrophysics - Solar and Stellar Astrophysics, 13. Climate action, Space and Planetary Science, Orbit (dynamics), Environmental science, Astrophysics - Instrumentation and Methods for Astrophysics, business, Space environment, Degradation (telecommunications)
Abstract

International audience; We present the lessons learned about the degradation observed in several space solar missions, based on contributions at the Workshop about On-Orbit Degradation of Solar and Space Weather Instruments that took place at the Solar Terrestrial Centre of Excellence (Royal Observatory of Belgium) in Brussels on 3 May 2012. The aim of this workshop was to open discussions related to the degradation observed in Sun-observing instruments exposed to the effects of the space environment. This article summarizes the various lessons learned and offers recommendations to reduce or correct expected degradation with the goal of increasing the useful lifespan of future and ongoing space missions.

Published
2013
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6. Identification of Sunspots on Full-Disk Solar Images Using Wavelet Analysis

Author

Djelloul Djafer, Mustapha Meftah, Abdanour Irbah, Unité de Recherche Appliquée en Energies Renouvelables (URAER), Ministère de l'Enseignement Supérieur et de la Recherche Scientifique [Algérie] (MESRS), STRATO - LATMOS, Laboratoire Atmosphères, Milieux, Observations Spatiales (LATMOS), and Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Université Pierre et Marie Curie - Paris 6 (UPMC)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Sunspot, 010504 meteorology & atmospheric sciences, Sunspots, [SDU.ASTR.SR]Sciences of the Universe [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], Sun radius, Wavelet transform, Astronomy and Astrophysics, Wavelet analysis, Radius, Spectral bands, Gaussian filters, [PHYS.ASTR.SR]Physics [physics]/Astrophysics [astro-ph]/Solar and Stellar Astrophysics [astro-ph.SR], 01 natural sciences, Noise (electronics), Edge detection, Wavelet, Space and Planetary Science, Observatory, 0103 physical sciences, 010303 astronomy & astrophysics, 0105 earth and related environmental sciences, Remote sensing
Abstract

International audience; A new method to detect sunspots on full-disk solar images, recorded in an optical wide spectral band and in the line of Ca ii K1, is presented. It is based on the compact wavelet transform and a process that automatically identifies the noise in the images of the Sun. This method estimates also its center and the limb positions with a precision of a few milliarcseconds. Precisions of 1 and 8 milliarcseconds are, respectively, found for the disk center position and the radius of simulated solar images. The results obtained on sunspot identification on solar images recorded during April 2002 at Meudon Observatory (France) reveal that we are able to detect 3.35 % additional sunspots compared to a manual method. Our method preserves the sunspot areas better than 95 %.

Published
2012
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7. A New Solar Spectrum from 656 to 3088 nm

Author

Meftah, M., primary, Damé, L., additional, Bolsée, D., additional, Pereira, N., additional, Sluse, D., additional, Cessateur, G., additional, Irbah, A., additional, Sarkissian, A., additional, Djafer, D., additional, Hauchecorne, A., additional, and Bekki, S., additional

Published
2017
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10. On the Determination and Constancy of the Solar Oblateness

Author

Meftah, M., primary, Irbah, A., additional, Hauchecorne, A., additional, Corbard, T., additional, Turck-Chièze, S., additional, Hochedez, J.-F., additional, Boumier, P., additional, Chevalier, A., additional, Dewitte, S., additional, Mekaoui, S., additional, and Salabert, D., additional

Published
2015
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12. Picard SODISM, a Space Telescope to Study the Sun from the Middle Ultraviolet to the Near Infrared

Author

Meftah, M., primary, Hochedez, J.-F., additional, Irbah, A., additional, Hauchecorne, A., additional, Boumier, P., additional, Corbard, T., additional, Turck-Chièze, S., additional, Abbaki, S., additional, Assus, P., additional, Bertran, E., additional, Bourget, P., additional, Buisson, F., additional, Chaigneau, M., additional, Damé, L., additional, Djafer, D., additional, Dufour, C., additional, Etcheto, P., additional, Ferrero, P., additional, Hersé, M., additional, Marcovici, J.-P., additional, Meissonnier, M., additional, Morand, F., additional, Poiet, G., additional, Prado, J.-Y., additional, Renaud, C., additional, Rouanet, N., additional, Rouzé, M., additional, Salabert, D., additional, and Vieau, A.-J., additional

Published
2013
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14. On-Orbit Degradation of Solar Instruments

Author

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

Published
2013
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16. SOVAP/ Picard, a Spaceborne Radiometer to Measure the Total Solar Irradiance.

Author

Meftah, M., Dewitte, S., Irbah, A., Chevalier, A., Conscience, C., Crommelynck, D., Janssen, E., and Mekaoui, S.

Subjects
*SOLAR oscillations, *SOLAR radiation, *SPECTRAL irradiance, *SPACE vehicles, *ASTRONOMICAL observations, *SOLAR cycle
Abstract

The Picard spacecraft was successfully launched on 15 June 2010, into a Sun-synchronous orbit. The mission represents one of the European contributions to solar observations and Essential Climate Variables (ECVs) measurements. The payload is composed of a Solar Diameter Imager and Surface Mapper (SODISM) and two radiometers: SOlar VAriability Picard (SOVAP) and PREcision MOnitor Sensor (PREMOS). SOVAP, a dual side-by-side cavity radiometer, measures the total solar irradiance (TSI). It is the sixth of a series of differential absolute-radiometer-type instruments developed and operated in space by the Royal Meteorological Institute of Belgium. The measurements of SOVAP in the summer of 2010 yielded a TSI value of 1362.1 W m with an uncertainty of ± 2.4 W m ( k=1). During the periods of November 2010 and January 2013, the amplitude of the changes in TSI has been on the order of 0.18 %, corresponding to a range of about 2.4 W m. [ABSTRACT FROM AUTHOR]

Published
2014
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17. Picard SODISM, a Space Telescope to Study the Sun from the Middle Ultraviolet to the Near Infrared.

Author

Meftah, M., Hochedez, J.-F., Irbah, A., Hauchecorne, A., Boumier, P., Corbard, T., Turck-Chièze, S., Abbaki, S., Assus, P., Bertran, E., Bourget, P., Buisson, F., Chaigneau, M., Damé, L., Djafer, D., Dufour, C., Etcheto, P., Ferrero, P., Hersé, M., and Marcovici, J.-P.

Subjects
*SPACE telescopes, *ULTRAVIOLET radiation, *NEAR infrared radiation, *SOLAR photosphere, *SOLAR activity, *SOLAR chromosphere, *SUN
Abstract

The Solar Diameter Imager and Surface Mapper (SODISM) onboard the Picard space mission provides wide-field images of the photosphere and chromosphere of the Sun in five narrow bandpasses centered at 215.0, 393.37, 535.7, 607.1, and 782.2 nm. The Picard spacecraft was successfully launched on 15 June 2010 into a Sun-synchronous dawn–dusk orbit. The Picard space mission represents a European asset in collecting solar observations useful to improve Earth climatic models. The scientific payload consists of the SODISM imager and of two radiometers, SOlar VAriability Picard (SOVAP) and PREcision MOnitor Sensor (PREMOS), which measure the Total Solar Irradiance (TSI) and part of the Solar Spectral Irradiance (SSI). The SODISM telescope continuously monitors solar activity from the middle ultraviolet to the near infrared spectral ranges and produces solar images that feed SSI reconstruction models. Further, SODISM probes the solar interior via a helioseismic analysis of the solar disc and limb images at 535.7 nm, and via astrometric investigations at the limb. The latter allows us to deduce the spectral dependence of the solar limb profile, and the asphericity of the Sun. Furthermore, SODISM data taken during the transit of Venus allow a determination of the absolute value of the solar diameter. This paper provides a detailed description of the SODISM instrument, including thermo-optical analysis, its different modes of observation, and its first performance in space. [ABSTRACT FROM AUTHOR]

Published
2014
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18. The Plate Scale of the SODISM Instrument and the Determination of the Solar Radius at 607.1 nm.

Author

Meftah, M., Hauchecorne, A., Crepel, M., Irbah, A., Corbard, T., Djafer, D., and Hochedez, J.-F.

Subjects
*DISKS (Astrophysics), *SOLAR activity, *SOLAR radiation, *SUN observations, *SOLAR telescopes, *CALIBRATION
Abstract

Knowledge of the Solar Diameter Imager and Surface Mapper (SODISM) plate scale is a fundamental parameter for obtaining the solar radius. We have determined the plate scale of the telescope on the ground and in flight onboard the Picard spacecraft. The results show significant differences; the main reason is that the conditions of observation are not the same. In addition, the space environment has an impact on the performance of a metrology instrument. Therefore, calibration in space and under the same conditions of observation is crucial. The transit of Venus allowed us to determine the plate scale of the SODISM telescope and hence the absolute value of the solar radius. The transit was observed from space by the Picard spacecraft on 5 – 6 June 2012. We exploited the data recorded by SODISM to determine the plate scale of the instrument, which depends on the characteristics of optical elements (mirrors, filters, or front window). The mean plate scale at 607.1 nm is found to be 1.0643 arcseconds pixel −1 with 3×10 −4 RMS. The solar radius at 607.1 nm from 1 AU is found to be equal to 959.86 arcseconds. [ABSTRACT FROM AUTHOR]

Published
2014
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