Download or read book METHODES ACTIVES SPATIO TEMPORELLES LARGE BANDE TECHNIQUES ET PERFORMANCES APPLICATION A DES SIGNAUX SONAR ET A DES SIGNAUX OBTENUS EN TRANSMISSION written by PHILIPPE.. GRAFFOULIERE and published by . This book was released on 1997 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: METHODES ACTIVES SPATIO-TEMPORELLES LARGE BANDE : TECHNIQUES ET PERFORMANCES. APPLICATION EN SONAR. CERTAINS PROCEDES D'ESTIMATION ET DE DETECTION SONT DITS ACTIFS, LORSQUE LA PREMIERE ETAPE CONSISTE EN L'EMISSION D'UN SIGNAL CONNU. NOUS NOUS SOMMES INTERESSES AUX METHODES DE TRAITEMENT DES SIGNAUX ISSUS DE CE TYPE D'EXPERIMENTATION, COMME LES SIGNAUX DE SONAR ACTIF OU DE TOMOGRAPHIE OCEANIQUE, EN S'APPUYANT SYSTEMATIQUEMENT SUR UNE HYPOTHESE DE BANDE LARGE. LA PREMIERE PARTIE EST CONSACREE AU TRAITEMENT D'ANTENNE ACTIF, ON Y RAPPELLE LES ESTIMATEURS OPTIMAUX, LES BORNES DE CRAMER-RAO ASSOCIEES, DANS DIVERSES CONFIGURATIONS D'ANTENNE ET DE SIGNAUX. LE TRAITEMENT OPTIMAL Y EST COMPARE A UNE METHODE RAPIDE INTERFEROMETRIQUE. LA DEUXIEME PARTIE EST CONSACREE A L'ESTIMATION RETARD DOPPLER, ON Y RAPPELLE LES ESTIMATEURS OPTIMAUX, LES BORNES DE CRAMER-RAO ASSOCIEES, EN INSISTANT SUR LES NOTIONS DE DECOUPLAGE DES ESTIMATEURS. LES RESULTATS SONT DISCUTES EN FONCTION DU DECOUPLAGE, DEPENDANT DE LA NATURE DES SIGNAUX. LA TROISIEME PARTIE EST CONSACREE A L'ESTIMATION ACTIVE SPATIO-TEMPORELLE HAUTE RESOLUTION. L'UTILISATION DE METHODES DE MAXIMUM DE VRAISEMBLANCE DANS CE BUT A ETE MONTREE POSSIBLE, MOYENNANT QUELQUES AMELIORATIONS APPORTEES. UNE EXTENSION A L'ESTIMATION HR RETARD-DOPPLER EST RAPIDEMENT DEVELOPPEE. LA QUATRIEME PARTIE EST CONSACREE A L'EVALUATION DE LA PERTE DE PERFORMANCES QUAND CES METHODES NE SONT PLUS OPTIMALES : SI LE BRUIT EST COLORE, L'ANTENNE DEFORMEE, LE SIGNAL EMIS DISTORDU... LA METHODE UTILISEE POUR CE FAIRE EST LE CALCUL DE PERTURBATIONS. DE NOMBREUSES SIMULATIONS CORROBORENT LES RESULTATS. ENFIN, LES METHODES HR SONT TESTEES AU MOYEN DE DEUX EXPERIMENTATIONS. LES RESULTATS OBTENUS SONT SATISFAISANTS, ET MONTRENT LA POSSIBILITE D'APPLIQUER CES METHODES AVEC SUCCES.
Download or read book Methodes actives spatio temporelles large bande techniques et performances application en sonar written by Philippe Graffouliere and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Modelling the Wireless Propagation Channel written by Fernando P¿rez Font¿n and published by John Wiley & Sons. This book was released on 2008-09-15 with total page 268 pages. Available in PDF, EPUB and Kindle. Book excerpt: A practical tool for propagation channel modeling with MATLAB® simulations. Many books on wireless propagation channel provide a highly theoretical coverage, which for some interested readers, may be difficult to follow. This book takes a very practical approach by introducing the theory in each chapter first, and then carrying out simulations showing how exactly put the theory into practice. The resulting plots are analyzed and commented for clarity, and conclusions are drawn and explained from the obtained results. Key features include: A unique approach to propagation channel modeling with accompanying MATLAB® simulations to demonstrate the theory in practice Contains step by step commentary and analysis of the obtained simulation results in order to provide a comprehensive and structured learning tool Covers a wide range of topics including shadowing effects, coverage and interference, Multipath Narrowband channel, Multipath Wideband channel, propagation in micro and pico-cells, the land mobile satellite (LMS) channel, the directional Multipath channel and MIMO and propagation effects in fixed radio links (terrestrial and satellite) The book comes with an accompanying website that contains the MATLAB® simulations and allows readers to try them out themselves Well suited for lab-use, as reference and as a self-learning tool both for advanced students and professionals Modeling the Wireless Propagation Channel: A simulation approach with MATLAB® will be best suited for postgraduate (Masters and PhD) students and practicing engineers in telecommunications and electrical engineering fields, who are seeking to familiarise themselves with the topic without too many formulas. The book will also be of interest to network engineers, system engineers and researchers
Download or read book Die Markfarbe als Unterscheidungsmerkmal von ephedra arten written by Widder. Felix and published by . This book was released on 1948 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analyse spatio temporelle des signaux large bande en vue de la tomographie acoustique oc anique written by Svetlana Bozinoski and published by . This book was released on 1996 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Cette etude s'insere dans le domaine de la tomographie acoustique oceanique (tao) par trajets multiples qui permet, a partir de l'analyse de la propagation des ondes acoustiques dans l'eau, d'etudier la structure a grande echelle de l'ocean. Classiquement, les differents trajets acoustiques sont identifies par leurs temps d'arrivee sur un capteur de mesure. L'originalite du travail presente ici est d'introduire des methodes d'analyse spatio-temporelle haute resolution comme outil pour la tao. Dans la phase d'identification des trajets, nous introduisons la dimension spatiale en considerant la reception des signaux sur un reseau de capteurs. Ceci permet de separer les trajets a la fois par leur temps de propagation et par leur direction d'arrivee. Nous presentons dans un premier temps la tomographie acoustique oceanique par trajets multiples. Puis, nous effectuons un rappel des methodes classiques d'analyse temporelle des signaux et nous posons les limites de ces methodes (resolution, information limitee au temps de propagation). Nous presentons ensuite une nouvelle methode d'analyse spatio-temporelle active et large bande qui permet l'estimation conjointe des directions et des temps d'arrivee. Cette methode est une extension de l'algorithme music et utilise la connaissance du signal emis. Ses caracteristiques sont presentees et ses performances (variance d'estimation des differents parametres) sont calculees. Cet algorithme est applique sur des donnees experimentales. Ceci permet de valider les modeles sous-jacent a la methode utilisee et met en evidence les gains apportes dans l'identification des trajets, que ce soit par l'aspect haute resolution de l'algorithme propose ou par l'information issue de l'analyse spatiale. Les donnees experimentales mettent aussi en evidence les limites d'utilisation de la methode
Download or read book Limitations Neurologiques Des Op rations A riennes written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Aerospace Medical Panel. Symposium and published by . This book was released on 1996 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Ecoacoustics written by Almo Farina and published by John Wiley & Sons. This book was released on 2017-07-24 with total page 367 pages. Available in PDF, EPUB and Kindle. Book excerpt: The sounds produced by geophonic, biophonic and technophonic sources are relevant to the function of natural and human modified ecosystems. Passive recording is one of the most non-invasive technologies as its use avoids human intrusion during acoustic surveys and facilitates the accumulation of huge amounts of acoustical data. For the first time, this book collates and reviews the science behind ecoaucostics; illustrating the principles, methods and applications of this exciting new field. Topics covered in this comprehensive volume include; the assessment of biodiversity based on sounds emanating from a variety of environments the best technologies and methods necessary to investigate environmental sounds implications for climate change and urban systems the relationship between landscape ecology and ecoacoustics the conservation of soundscapes and the social value of ecoacoustics areas of potential future research. An invaluable resource for scholars, researchers and students, Ecoacoustics: The Ecological Role of Sounds provides an unrivalled set of ideas, tools and references based on the current state of the field.
Download or read book Low Frequency Scattering written by George Dassios and published by Oxford University Press. This book was released on 2000 with total page 322 pages. Available in PDF, EPUB and Kindle. Book excerpt: Scattering theory deals with the interactions of waves with obstacles in their path, and low frequency scattering occurs when the obstacles involved are very small. This book gives an overview of the subject for graduates and researchers, for the first time unifying the theories covering acoustic, electromagnetic and elastic waves.
Download or read book Principles of Radar and Sonar Signal Processing written by Chevalier François Le and published by Artech House. This book was released on 2002 with total page 422 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Audio Effectiveness in Aviation written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development. Aerospace Medical Panel. Symposium and published by . This book was released on 1997 with total page 374 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Submarine Mass Movements and Their Consequences written by Vasilios Lykousis and published by Springer Science & Business Media. This book was released on 2007-09-14 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: With contributions from leading researchers in science and engineering, this book provides a global perspective on submarine mass movements and their consequences. Authors report on new findings from fundamental as well as site-specific studies from around the world. All studies relied on the most recent technologies, including multi-beam sonar imaging techniques, 3D seismic analysis, slope stability analysis, debris flow, and tsunami modeling.
Download or read book The Last Billion Years written by Atlantic Geoscience Society and published by Nimbus Publishing (CN). This book was released on 2001 with total page 220 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is about the history of the rocks and fossils of the Maritime Provinces of Canada (New Brunswick, Nova Scotia and PEI) over the last billion years. The book is beautifully illustrated in full colour, with original paintings of ancient vistas, over 150 photographs, and crisp explanatory diagrams and sketches.
Download or read book Decisions of the Commissioner of Patents written by and published by . This book was released on 1871 with total page 230 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Mobile WiMAX Systems written by Mohammed Khalid Salman Fadhil and published by CRC Press. This book was released on 2018-08-14 with total page 195 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents new models to enhance both capacity and coverage area in WiMAX FFR cellular network by considering the effect of interference of 18 base stations on the cell border users. The concepts provide a solid scientific base for analyzing and understanding WiMAX technology. This book enables the audience or researchers to understand the concept of the FFR technique. These basic concepts represent the important features of WiMAX technology which have been used to create new algorithms.
Download or read book Radio Propagation for Modern Wireless Systems written by Henry L. Bertoni and published by Pearson Education. This book was released on 1999-12-28 with total page 394 pages. Available in PDF, EPUB and Kindle. Book excerpt: To build wireless systems that deliver maximum performance and reliability, engineers need a detailed understanding of radio propagation. Drawing on over 15 years of experience, leading wireless communications researcher Henry Bertoni presents the most complete discussion of techniques for predicting radio propagation ever published. From its insightful introduction on spectrum reuse to its state-of-the-art real-world models for buildings, terrain, and foliage, Radio Propagation for Modern Wireless Systems delivers invaluable information for every wireless system designer. Coverage provides: A door to the understanding of radio wave propagation for the wireless channel. In-depth study of the effects on path loss of buildings, terrain, and foliage. A unified view of key propagation effects in narrowband and wideband systems, including spatial variation, angle of arrival, and delay spread. Readable account of diffraction at building corners, with worked out examples. Never-before-published coverage of mobile-to-mobile path loss in cities. Effective new ray-based models for site-specific predictions and simulation of channel statistics. Simulations of fast fading and shadow loss. From start to finish, Radio Propagation for Modern Wireless Systems presents sophisticated models–and compares their results with actual field measurements. With thorough coverage and extensive examples from both narrowband and wideband systems, it can help any wireless designer deliver more powerful, cost-effective services.
Download or read book Quaternary Vegetation Dynamics written by Jürgen Runge and published by CRC Press. This book was released on 2021-11-28 with total page 412 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book celebrates the relaunch of the African Pollen Database, presents state-of-the-art of modern and ancient pollen data from sub-Saharan Africa, and promotes Open Access science. Pollen grains are powerful tools for the study of past vegetation dynamics because they preserve well within sedimentary deposits and have a huge diversity in ornamentation that allows different taxa to be determined. The reconstruction of past vegetation from the examination of ancient pollen records thus can be used to characterize the nature of past landscapes (e.g. abundance of forests vs. grasslands), provide insights into changes in biodiversity, and gain empirical evidence of vegetation response to climatic change and human activity. In this, the 35th Volume of "Palaeoecology of Africa", we bring together new data and extensive synthetic reviews to provide novel insights into the relationships between human evolution, human activity, climate change and vegetation dynamics during the Quaternary, the last 2.6 million years. Current and ongoing climate and land-use change is exerting pressure on modern vegetation formations and threatening the livelihoods and wellbeing of many peoples in Africa. In this book the focus is on the Quaternary because it is during this geological period that the modern vegetation formations developed into their current configurations against a backdrop of high magnitude global climate change (glacial-interglacial cycles), human evolution, and a growing human land-use footprint. In this book the latest information is presented and collated from around the African continent to parameterize past vegetation states, identify the drivers of vegetation change, and assess the vegetation resilience to change. To achieve this research from two broad themes are covered: (i) the present is the key to the past (i.e. studies which improve our understanding of modern environments so that we can better interpret evidence from the past), and (ii) the past is the key to the future (i.e. studies which unlock information on how and why vegetation changed in the past so one can better anticipate trajectories of future change). This Open Access book will provide a strong foundation for future research exploring past ecological, environmental and climatic change within Africa and the surrounding islands. The book is organized regionally (covering western, eastern, central, and southern Africa) and it contains specialized articles focused on particular topics (such as modern pollen-vegetation relationships and fire as a driver of vegetation change), as well as regional and pan-African syntheses drawing together decades of research to assess key scientific questions (including the role of climate in driving vegetation change and the role of vegetation change in human evolution). These articles will be useful to students and teachers from high school to the highest level of university who are interested in the origins and dynamics of vegetation in Africa. Furthermore, it is also meant to provide societally relevant information that can act as an inspiration for the development of sustainable management practices for the future.
Download or read book Soundscape Ecology written by Almo Farina and published by Springer Science & Business Media. This book was released on 2013-10-28 with total page 326 pages. Available in PDF, EPUB and Kindle. Book excerpt: Soundscape Ecology represents a new branch of ecology and it is the result of the integration of different disciplines like Landscape ecology, Bioacoustics, Acoustic ecology, Biosemiotics, etc. The soundscape that is the object of this discipline, is defined as the acoustic context resulting from natural and human originated sounds and it is considered a relevant environmental proxy for animal and human life. With Soundscape Ecology Almo Farina means to offer a new cultural tool to investigate a partially explored component of the environmental complexity. For this he intends to set the principles of this new discipline, to delineate the epistemic domain in which to develop new ideas and theories and to describe the necessary integration with all the other ecological/environmental disciplines. The book is organized in ten chapters. The first two chapters delineate principles and theory of soundscape ecology. Chapters three and four describe the bioacoustic and communication theories. Chapter five is devoted to the human dimension of soundscape. Chapters six to eight regard the major sonic patterns like noise, choruses and vibrations. Chapter nine is devoted to the methods in soundscape ecology and finally chapter ten describes the application of the soundscape analysis.
