Download or read book Etude de la correction partielle en optique adaptative written by Philippe Mainguenaud and published by . This book was released on 1992 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book ETUDE DE LA CORRECTION PARTIELLE EN OPTIQUE ADAPTATIVE written by Jean-Marc Conan and published by . This book was released on 1995 with total page 341 pages. Available in PDF, EPUB and Kindle. Book excerpt: L'OPTIQUE ADAPTATIVE CORRIGE EN TEMPS REEL LES EFFETS DE LA TURBULENCE ATMOSPHERIQUE ET PERMET D'OBTENIR DES IMAGES A HAUTE RESOLUTION AVEC DES INSTRUMENTS ASTRONOMIQUES DE GRANDES DIMENSIONS. APRES UNE ANALYSE THEORIQUE DE L'EVOLUTION TEMPORELLE DES FRONTS D'ONDE TURBULENTS, NECESSAIRE A UNE BONNE MODELISATION DU SYSTEME D'OPTIQUE ADAPTATIVE, J'ETUDIE LA QUALITE DES IMAGES DONNEES PAR UN TEL SYSTEME ; LA CORRECTION DEVIENT PARTIELLE POUR LES FAIBLES LONGUEURS D'ONDE D'IMAGERIE OU LORSQUE LES CONDITIONS DE TURBULENCE SONT PARTICULIEREMENT SEVERES. UNE SIMULATION NUMERIQUE RIGOUREUSE DU SYSTEME D'OPTIQUE ADAPTATIVE PERMET D'ILLUSTRER LES RESULTATS THEORIQUES. JE COMPARE ENSUITE LE RAPPORT SIGNAL A BRUIT DE L'IMAGERIE LONGUE POSE ET DES TECHNIQUES SPECKLES EN PRESENCE DE CORRECTION PAR L'OPTIQUE ADAPTATIVE. JE MONTRE QUE CES DERNIERES SONT PARTICULIEREMENT ADAPTEES AUX CAS DE CORRECTIONS TRES PARTIELLES ALORS QUE L'IMAGERIE LONGUE POSE DOIT ETRE PLUTOT RESERVEE AUX CAS DE BONNES CORRECTIONS. QUELLE QUE SOIT LA TECHNIQUE UTILISEE, LA RESTITUTION D'UN OBJET A UNE RESOLUTION PROCHE DE LA DIFFRACTION NECESSITE UN TRAITEMENT D'IMAGE A POSTERIORI. JE DISCUTE ESSENTIELLEMENT DES TECHNIQUES DE DECONVOLUTION APPLICABLES AUX IMAGES LONGUE POSE OBTENUES EN OPTIQUE ADAPTATIVE: DECONVOLUTION EN AVEUGLE, OU UTILISANT UNE ESTIMATION DE LA FONCTION D'ETALEMENT DE POINT A PARTIR DES DONNEES DE L'ANALYSEUR DE FRONT D'ONDE OU D'UNE IMAGE D'ETOILE DE CALIBRATION. DE CES RESULTATS OBTENUS EN IMAGERIE A UN TELESCOPE JE DEDUIS LES PERFORMANCES D'UN INTERFEROMETRE CONSTITUE DE GRANDS TELESCOPES EQUIPES DE SYSTEMES D'OPTIQUE ADAPTATIVE. J'ESTIME NOTAMMENT LE RAPPORT SIGNAL A BRUIT SUR LES VISIBILITES MESUREES EN LONGUE POSE OU EN TECHNIQUE SPECKLE

Download or read book Correction partielle et anisoplan tisme en optique adaptative written by Thierry Fusco and published by . This book was released on 2000 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt: La correction partielle et l'anisoplanétisme sont les deux limitations fondamentales des systèmes d'Optique Adaptative (OA). Le but de cette thèse est l'étude de techniques permettant de s'affranchir de ces limitations. Dans un premier temps une étude statistique du phénomène d'anisoplanètisme et de la correction partielle est effectuée. Pour s'affranchir du flou résiduel dans l'image, des méthodes de traitement d'images a posteriori sont mises en œuvre. Elles sont d'abord développées dans le cadre d'images isoplanétiques. Elles se basent sur une approche probabiliste du problème qui permet d'obtenir des précisions tant photométriques qu'astrométriques bien supérieures aux algorithmes de déconvolution classiquement utilisés en astronomie. Une extension de ces techniques à l'imagerie anisoplanétique est ensuite proposée. Une expression théorique de la dégradation de la FEP dans le champ est calculée puis intégrée dans un algorithme de traitement d'images de champs stellaires. La technique reste cependant limitée par la chute du rapport signal à bruit pour les grands angles. Pour augmenter ce rapport signal à bruit et donc accéder à des champs plus importants, on doit alors modifier les systèmes d'OA en prenant en compte les effets d'anisoplanétisme. C'est le concept d'OA multiconjuguée (AOMC). Une OAMC se compose de plusieurs miroirs déformables. L'étude proposée dans la thèse porte sur le problème de la reconstruction de front d'onde à grand champ et de la commande spatiale des miroirs déformables. Des méthodes d'inversion sont développées en tenant compte de la statistique de la phase turbulente pour régulariser le problème et permettre une reconstruction optimale. (...)

Download or read book Correction partielle et anisoplan tisme en Optique Adaptive written by Thierry Fusco and published by . This book was released on 2000 with total page 307 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bayesian Approach to Inverse Problems written by Jérôme Idier and published by John Wiley & Sons. This book was released on 2013-03-01 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Many scientific, medical or engineering problems raise the issue of recovering some physical quantities from indirect measurements; for instance, detecting or quantifying flaws or cracks within a material from acoustic or electromagnetic measurements at its surface is an essential problem of non-destructive evaluation. The concept of inverse problems precisely originates from the idea of inverting the laws of physics to recover a quantity of interest from measurable data. Unfortunately, most inverse problems are ill-posed, which means that precise and stable solutions are not easy to devise. Regularization is the key concept to solve inverse problems. The goal of this book is to deal with inverse problems and regularized solutions using the Bayesian statistical tools, with a particular view to signal and image estimation. The first three chapters bring the theoretical notions that make it possible to cast inverse problems within a mathematical framework. The next three chapters address the fundamental inverse problem of deconvolution in a comprehensive manner. Chapters 7 and 8 deal with advanced statistical questions linked to image estimation. In the last five chapters, the main tools introduced in the previous chapters are put into a practical context in important applicative areas, such as astronomy or medical imaging.

Download or read book Advances in Imaging and Electron Physics written by Peter W. Hawkes and published by Elsevier. This book was released on 2011-07-29 with total page 327 pages. Available in PDF, EPUB and Kindle. Book excerpt: Advances in Imaging and Electron Physics merges two long-running serials-Advances in Electronics and Electron Physics and Advances in Optical and Electron Microscopy. This series features extended articles on the physics of electron devices (especially semiconductor devices), particle optics at high and low energies, microlithography, image science and digital image processing, electromagnetic wave propagation, electron microscopy, and the computing methods used in all these domains. Includes grey systems and grey information Discusses Phase diversity Recent developments in the imaging of magnetic domains Explores stochastic deconvolution over groups

Download or read book Adaptive Optics and Applications written by and published by . This book was released on 1997 with total page 642 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Adaptive Optical System Technologies written by and published by . This book was released on 1998 with total page 512 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advanced Wavefront Control written by and published by . This book was released on 2003 with total page 222 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Journal of the Optical Society of America written by and published by . This book was released on 2006 with total page 524 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Optics in Atmospheric Propagation and Adaptive Systems written by and published by . This book was released on 1999 with total page 254 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Advances in Adaptive Optics II written by and published by . This book was released on 2006 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Messenger written by and published by . This book was released on 2000 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Bayesian Inference for Inverse Problems written by Ali Mohammad-Djafari and published by SPIE-International Society for Optical Engineering. This book was released on 1998 with total page 396 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Three dimensional and Multidimensional Microscopy written by and published by . This book was released on 2006 with total page 216 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Aeronautical Journal written by and published by . This book was released on 1995 with total page 522 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Propagation and Imaging Through the Atmosphere written by and published by . This book was released on 2000 with total page 218 pages. Available in PDF, EPUB and Kindle. Book excerpt: