Search

Your search keyword '"J.-M. Geffrin"' showing total 8 results
Start Over Author "J.-M. Geffrin" Topic 02 engineering and technology
8 results on '"J.-M. Geffrin"'

1. Full-Wave Indoor Measurements’ Cross-Validation With the Model Demos for Foliage Penetrating Applications

Author

O. Meyer, Massimiliano Casaletti, J.-M. Geffrin, C. Dahon, Hassan Saleh, L. Hettak, Hélène Roussel, Sorbonne Université (SU), Institut FRESNEL (FRESNEL), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Laboratoire d'Electronique et Electromagnétisme (L2E), Laboratoire Génie électrique et électronique de Paris (GeePs), CentraleSupélec-Sorbonne Université (SU)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), HIPE (HIPE), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Anechoic chamber, Field (physics), Scattering, Monostatic measurements, Acoustics, Foliage Penetrating, 0211 other engineering and technologies, Domain decomposition methods, 02 engineering and technology, Dielectric, Geotechnical Engineering and Engineering Geology, Radio spectrum, Cross-validation, law.invention, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, law, radar detection, Electrical and Electronic Engineering, Radar, 021101 geological & geomatics engineering
Abstract

International audience; For foliage penetrating (FoPen) radar development, we previously developed a hybrid volume-surface model, named Domain dEcomposition Model (DEMOS), to evaluate the electromagnetic scattering from large scenes composed by targets (metallic objects) placed in a natural environment (dielectric object). In this letter, we compare the scattered field obtained by DEMOS with the quasi-monostatic measurements done in an anechoic chamber on scaled models composed of dielectric and metallic structures. For all measurements, we consider both polarizations, HH and VV. Our final objective is to determine the optimal configurations for the detection of a target placed in a forest environment in the very high-frequency (VHF)-UHF frequency bands.

Published
2020
Full Text
View/download PDF

2. Towards Asteroid Tomography: Modellings and Measurements Using an Analogue Model

Author

Liisa-Ida Sorsa, Sampsa Pursiainen, J.-M. Geffrin, Christelle Eyraud, Wlodek Kofman, Alain Herique, Institut FRESNEL (FRESNEL), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Tampere University of Applied Sciences [Finland], Institut de Planétologie et d'Astrophysique de Grenoble (IPAG), Centre National d'Études Spatiales [Toulouse] (CNES)-Observatoire des Sciences de l'Univers de Grenoble (OSUG ), Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France -Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Météo-France, Space Research Centre [Torun], Polska Akademia Nauk = Polish Academy of Sciences (PAN), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), and Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Savoie Mont Blanc (USMB [Université de Savoie] [Université de Chambéry])-Centre National de la Recherche Scientifique (CNRS)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Université Grenoble Alpes (UGA)

Subjects
Electromagnetic field, Physics, Solar System, Tomographic reconstruction, 020208 electrical & electronic engineering, 020206 networking & telecommunications, 02 engineering and technology, Inverse problem, Computational physics, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Microwave imaging, Asteroid, Frequency domain, 0202 electrical engineering, electronic engineering, information engineering, Astrophysics::Earth and Planetary Astrophysics, Focus (optics), ComputingMilieux_MISCELLANEOUS
Abstract

The interior structures of the comets and asteroids, still poorly known, might hold a unique key to understand the early Solar System. Considering the interaction of an illuminated electromagnetic wave with this kind of targets, these ”objects” are very large compared to the applicable wavelength. Consequently, tomographic imaging of such targets, i.e., reconstructing their interior structure via multiple measurements, constitutes a challenging inverse problem. To reach this objective and to develop and test inverse algorithms, we need to investigate electromagnetic fields that have interacted with structures analogous to real asteroids and comets. In this study, we focus on the acquisition of these fields considering three methods: calculated fields obtained with (1) time and (2) frequency domain methods and (3) microwave measurements performed for an analogue model, i.e., a small-scale asteroid model.

Published
2020
Full Text
View/download PDF

3. Influence of the description of the scattering matrix on permittivity reconstruction with a quantitative imaging procedure: polarization effects

Author

Hassan Saleh, J.-M. Geffrin, Christelle Eyraud, Institut FRESNEL (FRESNEL), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Centre Commun de Ressources en Microondes (CCRM), HIPE (HIPE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)

Subjects
Permittivity, 02 engineering and technology, Iterative reconstruction, 01 natural sciences, Light scattering, 010309 optics, Optics, Optical coherence tomography, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, medicine, Circular polarization, ComputingMilieux_MISCELLANEOUS, Physics, medicine.diagnostic_test, business.industry, Scattering, Mathematical analysis, 020206 networking & telecommunications, Polarization (waves), Atomic and Molecular Physics, and Optics, Electronic, Optical and Magnetic Materials, Nonlinear system, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Computer Vision and Pattern Recognition, business, [SPI.SIGNAL]Engineering Sciences [physics]/Signal and Image processing
Abstract

International audience; This paper focuses on the role of polarization-and more specifically, the effect of its selection-in 3D quantitative imaging obtained from scattered field measurements. Although polarization is now commonly used in linear imaging procedures (when unknowns are linked by a linear relationship to the measured signal), the influence of polarization choice is generally ignored in nonlinear imaging problems. In this paper, we propose a formulation to obtain the 3D permittivity map, by a nonlinear imaging procedure, from the scattering matrix. This allows one to select, from the same data set, the desired polarization case as input data for the imaging algorithm. We present a study of the influence of the input data polarization choice on the reconstructed per-mittivity map. This work shows that a suitable basis choice for the description of the scattering matrix and an appropriate selection of the element of this scattering matrix can greatly improve imaging results.

Published
2018
Full Text
View/download PDF

4. Optimization of the experimental parameters and of the noise of scattering measurements for inverse scattering applications

Author

H. Saleh, Christelle Eyraud, J.-M. Geffrin, Centre Commun de Ressources en Microondes (CCRM), HIPE (HIPE), Institut FRESNEL (FRESNEL), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Noise measurement, Measurement uncertainty, Bayesian probability, 02 engineering and technology, 01 natural sciences, Antenna measurements, 010309 optics, Scattering, symbols.namesake, Optics, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Power measurement, Physics, business.industry, Permittivity measurement, 020206 networking & telecommunications, Inversion (meteorology), [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Gaussian noise, Inverse scattering problem, Permittivity, symbols, business, Algorithm
Abstract

International audience; This paper presents an attempt to optimize the technical settings of the experimental setup of the CCRM in Marseille in order to reduce the experimental noise and test its influence on inverse scattering reconstructions. This work has been done with the constraint of keeping a Gaussian noise distribution. The reconstructions, obtained from both simulation and measurements of the field scattered by the target under study, a spiral, were obtained with an inversion algorithm based on a Bayesian approach. Moreover, two different reconstructions from measurements are discussed here, with and without taking into account in the inversion algorithm the distribution of the noise affecting the measurements. Some preliminary conclusions are drawn.

Published
2017
Full Text
View/download PDF

5. Sphere dimers of high refractive index dielectric particles as elementary units for building optical switching devices

Author

Ángela I. Barreda, Hassan Saleh, Amelie Litman, Fernando Moreno, Francisco González, J.-M. Geffrin, Group of Optics. Department of Applied Physics, Universidad de Cantabria [Santander], HIPE (HIPE), Institut FRESNEL (FRESNEL), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Centre Commun de Ressources en Microondes (CCRM), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
0303 health sciences, Chemistry, business.industry, High-refractive-index polymer, Scattering, Linear polarization, Physics::Optics, Optical polarization, 02 engineering and technology, Dielectric, 021001 nanoscience & nanotechnology, Polarization (waves), [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, 03 medical and health sciences, Optics, [SPI.OPTI]Engineering Sciences [physics]/Optics / Photonic, Optoelectronics, 0210 nano-technology, business, Refractive index, ComputingMilieux_MISCELLANEOUS, Excitation, 030304 developmental biology
Abstract

Semiconductors like Si, Ge (and other compounds like GaAs, GaP, etc) show high values of their refractive index and low absorption in the visible (VIS) and near-infrared (NIR) ranges. Nanoparticles made of these high refractive index (HRI) materials have been recently proposed as an alternative to metallic ones to overcome their inherent ohmic losses. In addition, the excitation of coherent electric and magnetic resonances makes these HRI nanoparticles to become basic to build multifunctional elements in optical devices for controlling the directionality of the scattered radiation. Here, we present unambiguous experimental evidence in the microwave range that a dimer of spherical High Refractive Index dielectric particles behaves as an elementary block for building switching devices whose binary state only depends on the polarization of the incident radiation. The corresponding analysis has been carried out by means of the linear polarization degree of the scattered radiation at the right angle scattering configuration.

Published
2017
Full Text
View/download PDF

6. On the interest of a bistatic radar cross section setup to measure various scattering quantities

Author

Hassan Saleh, Christelle Eyraud, Amelie Litman, J.-M. Geffrin, HIPE (HIPE), Institut FRESNEL (FRESNEL), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Centre Commun de Ressources en Microondes (CCRM), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Physics, Angular range, 010504 meteorology & atmospheric sciences, business.industry, Scattering, Extinction cross section, 020206 networking & telecommunications, 02 engineering and technology, Scale invariance, 01 natural sciences, symbols.namesake, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Optics, Maxwell's equations, 0202 electrical engineering, electronic engineering, information engineering, symbols, Degree of polarization, business, Microwave, Bistatic radar cross section, 0105 earth and related environmental sciences
Abstract

International audience; This paper describes how the bistatic radar cross section (RCS) experimental setup of the “Centre Commun de Ressources en Microondes” (CCRM) was used to precisely determine various scattering quantities and how we took profit of the large scattering angular range available with this setup. Results on extinction cross section, linear degree of polarization and other scattering quantities of interest are presented. We also show how those results are interesting in different domains where scattering phenomena are studied thanks to the scale invariance properties of the Maxwell equations using the so called microwave analogy.

Published
2017
Full Text
View/download PDF

7. Interlaboratory comparisons of radar cross section measurements by the 'GTi', criteria suggestions

Author

S. Leman, R. Guillerey, Pierre Massaloux, F. Daout, G-P Piau, J C Castelli, Christelle Eyraud, J.-M. Geffrin, S. Fargeot, Fabrice Comblet, G. Maze-Merceur, ONERA - The French Aerospace Lab [Palaiseau], ONERA-Université Paris Saclay (COmUE), Lab-STICC_ENSTAB_MOM_PIM, Laboratoire des sciences et techniques de l'information, de la communication et de la connaissance (Lab-STICC), Université européenne de Bretagne - European University of Brittany (UEB)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Télécom Bretagne-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-Université européenne de Bretagne - European University of Brittany (UEB)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Télécom Bretagne-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Systèmes et Applications des Technologies de l'Information et de l'Energie (SATIE), École normale supérieure - Cachan (ENS Cachan)-Université Paris-Sud - Paris 11 (UP11)-Institut Français des Sciences et Technologies des Transports, de l'Aménagement et des Réseaux (IFSTTAR)-École normale supérieure - Rennes (ENS Rennes)-Université de Cergy Pontoise (UCP), Université Paris-Seine-Université Paris-Seine-Conservatoire National des Arts et Métiers [CNAM] (CNAM), HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-HESAM Université - Communauté d'universités et d'établissements Hautes écoles Sorbonne Arts et métiers université (HESAM)-Centre National de la Recherche Scientifique (CNRS), HIPE (HIPE), Institut FRESNEL (FRESNEL), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Airbus Defence and Space [Les Mureaux], ASTRIUM, DGA/CELAR, Nexio, Centre d'études scientifiques et techniques d'Aquitaine (CESTA), Direction des Applications Militaires (DAM), Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Airbus Group Innovations [Suresnes], Airbus [France], GDR Ondes, École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Télécom Bretagne-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Université européenne de Bretagne - European University of Brittany (UEB)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS)-École Nationale d'Ingénieurs de Brest (ENIB)-Université de Bretagne Sud (UBS)-Université de Brest (UBO)-Télécom Bretagne-Institut Brestois du Numérique et des Mathématiques (IBNM), Université de Brest (UBO)-Université européenne de Bretagne - European University of Brittany (UEB)-École Nationale Supérieure de Techniques Avancées Bretagne (ENSTA Bretagne)-Institut Mines-Télécom [Paris] (IMT)-Centre National de la Recherche Scientifique (CNRS), Université Paris-Seine-Université Paris-Seine-Conservatoire National des Arts et Métiers [CNAM] (CNAM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Airbus Defence and Space, and Airbus Group

Subjects
Radar cross-section, Engineering, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Anechoic chamber, business.industry, 0202 electrical engineering, electronic engineering, information engineering, Systems engineering, Electronic engineering, Measurement uncertainty, 020206 networking & telecommunications, 02 engineering and technology, business
Abstract

International audience; A comparison of Radar Cross Section (RCS) measurement results between several French measurement indoor facilities has been organized in the framework of a French Working Group (Groupe de Travail sur les incertitudes en chambre anéchoïque: GTi), dealing with measurement uncertainties in anechoic chamber. The GTi involves 22 laboratories that are either industrial or academic research ones, or laboratories depending on public organisms. Three tasks have been defined: 1/ State of the art, 2/ Comparisons of RCS measurements, 3/ Comparisons of Antenna Measurements. This paper deals with the second task, in which 8 laboratories are engaged. The motivations and the tasks are described in this paper and results will be presented at the conference. Comparison criteria will also be proposed.

Published
2017
Full Text
View/download PDF

8. Plane Wave and Gaussian Beam Scattering by Long Dielectric Cylinders: 2.5D Simulations versus Measurements

Author

S. Van den Bulcke, Johan Stiens, J. M. Geffrin, Ann Franchois, L. Zhang, Dept. of Information Techn. (INTEC), Universiteit Gent = Ghent University [Belgium] (UGENT), Department of Electronics and Informatics (ETRO), Université de Bruxelles, HIPE (HIPE), Institut FRESNEL (FRESNEL), Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU)-Centre National de la Recherche Scientifique (CNRS)-École Centrale de Marseille (ECM)-Aix Marseille Université (AMU), Idehara, Toshitaka, Electronics and Informatics, Laboratorium for Micro- and Photonelectronics, Universiteit Gent = Ghent University (UGENT), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Gaussian, Plane wave, Millimeter waves, 02 engineering and technology, 01 natural sciences, 2.5D simulations and measurements, 010309 optics, Scattering, symbols.namesake, Optics, 0103 physical sciences, 0202 electrical engineering, electronic engineering, information engineering, Classical electromagnetism, Vectorial Gaussian beam, Electrical and Electronic Engineering, Instrumentation, Physics, Radiation, business.industry, 020206 networking & telecommunications, Condensed Matter Physics, [SPI.ELEC]Engineering Sciences [physics]/Electromagnetism, Extremely high frequency, symbols, Development (differential geometry), business, Microwave, Gaussian beam
Abstract

International audience; For the development of millimeter wave imaging systems, it is important to be able to simulate some representative scattering configurations. Typically, Gaussian beams are used in active imaging systems. Since these beams only illuminate a spatially limited region, many objects can be treated as infinitely long 2D (in)homogenous cylinders. However, the incident Gaussian beams have a 3D character. Therefore, a dedicated 2.5D scattering simulator was developed. In this paper, simulation results obtained with this simulator are compared to measurements obtained from a bi-static microwave set-up and from a W-band millimeter wave set-up. Comparison of simulations and measurements proves that the 2.5D algorithm is a good simulation tool to study scattering of long inhomogeneous cylinders, illuminated by 3D plane waves or 3D Gaussian beams under different elevation angles.

Published
2008
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results