Tesis sobre el tema "Satellites artificiels – Systèmes de communication"
Crea una cita precisa en los estilos APA, MLA, Chicago, Harvard y otros
Consulte los 50 mejores tesis para su investigación sobre el tema "Satellites artificiels – Systèmes de communication".
Junto a cada fuente en la lista de referencias hay un botón "Agregar a la bibliografía". Pulsa este botón, y generaremos automáticamente la referencia bibliográfica para la obra elegida en el estilo de cita que necesites: APA, MLA, Harvard, Vancouver, Chicago, etc.
También puede descargar el texto completo de la publicación académica en formato pdf y leer en línea su resumen siempre que esté disponible en los metadatos.
Explore tesis sobre una amplia variedad de disciplinas y organice su bibliografía correctamente.
Cantillo, Juan. "Codage multi-couches pour systèmes de communication par satellites". Phd thesis, Paris, ENST, 2008. https://pastel.hal.science/pastel-00005209.
Texto completoThis thesis addresses the error control problem for satellite links from the perspective of cross-layer design. At the crossroads of qos-related constraints, devices complexity and efficient spectrum use, error control is indeed a key aspect of wireless communications - particularly crucial in the satellite context - where cross-layer enhancements can play an important role. After a thorough introduction to cross-layer design, the first part of this work focuses specifically on the error control strategy of early DVB satellites, where redundancies between the channel decoder and the adaptation layers are set to light in order to propose a joint bandwidth-efficient error control policy. The focus then moves to second-generation DVB satellites and the definition of the novel, IP-centric and cross-layer friendly GSE encapsulation protocol, where results from the aforementioned study were successfully applied. Finally, a whole new cross-layer framework called HERACLES is introduced, offering efficient and overhead-free error correction capabilities for almost any layer of a protocol stack and being patented at the moment of writing these words. The results of the overall work show the strengths of an integrated approach to error control, and open the way for innovative cross-layer mechanisms to be deployed in next-generation communications networks
Cantillo, Juan. "Codage multi-couches pour systèmes de communication par satellites". Phd thesis, Télécom ParisTech, 2008. http://pastel.archives-ouvertes.fr/pastel-00005209.
Texto completoKiatmanaroj, Kata. "Allocation de fréquence dans les systèmes de communication par satellites de type SDMA". Phd thesis, Université Paul Sabatier - Toulouse III, 2012. http://tel.archives-ouvertes.fr/tel-00715148.
Texto completoMeddeb, Souad. "Identification des filtres de Volterra et des modèles bilinéaires : application à la communication par satellite". Toulouse, INPT, 2000. http://www.theses.fr/2000INPT036H.
Texto completoMalicorne, Marie. "Analyse des performances de systèmes de navigation par satellites pour les applications en environnement urbain". École nationale supérieure de l'aéronautique et de l'espace (Toulouse ; 1972-2007), 2001. http://www.theses.fr/2001ESAE0014.
Texto completoJegham, Nizar. "Performances des applications IP dans les systèmes de communications par satellite : cas du DVB-RCS et du DVB-S2". Phd thesis, Université Paris-Est, 2008. http://tel.archives-ouvertes.fr/tel-00495622.
Texto completoTou, Ihsane. "Adaptation de la couche transport des systèmes de communication hybrides satellite/terrestre". Phd thesis, Université Paul Sabatier - Toulouse III, 2012. http://tel.archives-ouvertes.fr/tel-00807583.
Texto completoCallec, Vincent. "Systèmes antennaires reconfigurables pour l'observation spatiale". Phd thesis, INSA de Rennes, 2013. http://tel.archives-ouvertes.fr/tel-00935319.
Texto completoSuquet, Etienne. "Caractérisation multi-fréquence du canal de propagation et modélisation de la similitude en fréquence instantanée pour optimiser des liens satellitaires en bandes Ka et Q/V". Electronic Thesis or Diss., Université de Toulouse (2023-....), 2024. http://www.theses.fr/2024TLSES019.
Texto completoThe characterization of the propagation channel is a major issue in order to optimize satellite communication systems. At Ka-band, or at higher frequency bands, signal attenuation is almost exclusively caused by the troposphere, and particularly rain, whose attenuation can reach levels preventing any communication. Frequency scaling is a technique aiming to determine the tropospheric attenuation at a target frequency, from measurements made at another frequency using a beacon receiver. This technique is useful to obtain precise attenuation statistics at a target frequency, or to determine in real time the attenuation on a satellite uplink, from a measurement of the attenuation on the downlink, in order to optimise fade mitigation techniques. This thesis activity consisted in studying, on the one hand, the sources of error affecting attenuation measurements, collected using beacon receivers, in order to quantify them, or even, if possible, to correct them. On the other hand, several promising frequency scaling models of the literature are reviewed, and improvements are considered. In particular, it is shown that frequency scaling models based on micro-physical modelling are of interest for tropical climates
Baudin, Roland. "Évaluation du taux d'erreur de bits dans des chaines non-linéaires de communications numériques". Toulouse, INPT, 1992. http://www.theses.fr/1992INPT086H.
Texto completoMillerioux, Jean-Pierre. "Techniques de détection multi-utilisateurs pour les communications multifaisceaux par satellite". Phd thesis, Télécom ParisTech, 2006. http://pastel.archives-ouvertes.fr/pastel-00002006.
Texto completoÖnen, Suna Melek. "La Sécurité des communications multipoints dans les réseaux satellitaires: Une approche centrée sur la satisfaction des utilisateurs". Phd thesis, Télécom ParisTech, 2005. http://pastel.archives-ouvertes.fr/pastel-00001363.
Texto completoIsmaïl, Mohamed Amine. "Study and optimization of data protection, bandwidth usage and simulation tools for wireless networks". Nice, 2010. http://www.theses.fr/2010NICE4074.
Texto completoToday, many technical challenges remain in the design of wireless networks to support emerging services. The main contributions of this thesis are three-fold in addressing some of these issues. The first contribution addresses the reliability of wireless links, in particular through data protection against long fading time (also known as slow fading) in the context of a direct satellite-to-mobile link. We propose an innovative algorithm, called Multi Burst Sliding Encoding (MBSE), that extends the existing DVB-H intra-burst (MPEFEC) protection to an inter-burst protection. Our MBSE algorithm allows complete burst losses to be recovered, while taking into account the specificity of mobile hand-held devices. Based on an optimized data organization, our algorithm provides protection against long term fading, while still using the Reed-Solomon code already implemented in mobile hand-held chipsets. MBSE has been approved by the DVB Forum and was integrated in the DVB-SH standard in which it now plays a key role. The second contribution is related to the practical optimization of bandwidth usage in the context of wireless links. We have proposed WANcompress, a bandwidth compression technique for detecting and eliminating redundant network traffic by sending only a label instead of the original packets. It differs from standard compression techniques in that it removes redundant patterns over a large range of time (days/weeks, i. E. Giga-bytes) where as existing compression techniques operate on a smaller windwos scales (seconds, i. E. Few kilo-bytes). We performed intensive experiments that achieved compression factors up to 25 times, and acceleration factors up to 22 times. In a corporate trial conducted over a WiMAX network for one week, WANcompress improved the bitrate up to 10 times, and on average 33% of the bandwidth was saved. The third contribution is related to the simulation of wireless networks. We have proposed a 802. 16 WiMAX module for the widely used ns-3 simulator. Our module provides a detailed and standard-compliant implementation of the Point to Multi-Point (PMP) topology with Time Division Duplex (TDD) mode. It supports a large number of features, thus enabling the simulation of a rich set of WiMAX scenarios, and providing close-to-real results. These features include Quality of Service (QoS) management, efficient scheduling for both up-link and downlink, packet classification, bandwidth management, dynamic flow creation, as well as scalable OFDM physical layer simulation. This module was merged with the main development branch of the ns-3 simulator, and has become one of its standard features as of version v3. 8
Zamoum, Selma. "Random access techniques for satellite communications". Thesis, Toulouse, INPT, 2019. http://www.theses.fr/2019INPT0116.
Texto completoThe effective coverage of satellites and the technology behind have motivated many actors to develop efficient communications for Internet access, television and telephony. For a long time, reservation resources of Demand Assignment Multiple Access (DAMA) techniques have been largely deployed in the return link of satellite communications, occupying most of the frequency bandwidth. However, these resources cannot follow the technological growth with big users communities in applications like the Internet of Things and Machine to Machine communications. Especially because the Round Trip Time is significant in addition to a potential underuse of the resources. Thus, access protocols based on ALOHA took over a big part of the Random Access (RA) research area and have considerably evolved lately. CRDSA have particularly put its fingerprint in this domain, which inspired many different techniques. In this context, a complementary method, called MARSALA comes to unlock CRDSA when packets can no longer be retrieved. This actually involves a correlation complexity related to packet localization which is necessary for replicas combinations that results in a potentially higher signal power. Accordingly, the main goal of this PhD research is to seek for effective and less complex alternatives. More precisely, the core challenge focuses on the way to manage multi-user transmissions and solve interference at reception, with the smallest complexity. In addition, the loop phenomenon which occur when multiple users transmit their packets at the same positions is tackled as it creates an error floor at the packet loss ratio performance. Synchronous and asynchronous solutions are proposed in this thesis, mainly based on providing the transmitter and the receiver with a shared prior information that could help reduce the complexity, mitigate the loop phenomenon and enhance the system performance. An in-depth description and analysis of the proposed techniques are presented in this dissertation
Loireau, Maud. "Espaces, ressources, usages : spatialisation des interactions dynamiques entre les systèmes sociaux et les systèmes écologiques au Sahel nigérien". Montpellier 3, 1998. http://www.theses.fr/1998MON30058.
Texto completoPignoly, Vincent. "Étude de codes LDPC pour applications spatiales optiques et conception des décodeurs associés". Thesis, Bordeaux, 2021. http://www.theses.fr/2021BORD0025.
Texto completoDigital communication systems are everywhere in our daily life. The evolution of needs implies the research and development of innovative solutions for future communication systems. Considering space digital communications, most satellites use radiofrequency links to communicate with the Earth. To minimize bandwith usage and increase throughputs, digital communication technologies based on optical links represent an interesting alternative. However, luminous energy is absorbed by particules that are present in the Earth's atmosphere. These perturbations implies new issues and new coding schemes must be developed to cope with them.LDPC codes are an error correction code family. Their performance near Shannon's limit makes them an attractive solution for digital communication systems. They have been selected in Wifi and 5G standards to achieve very high throughputs (several Gbps). They were also adopted in CSSDS and DVB-S2 standards for space applications.This thesis is about the study and the hardware implementation of coding schemes applied on optical links for space digital communication systems. The first contribution is the study of a coding scheme for an optical downlink with a soft input decoder on Earth. In this study, we developed a hardware architecture capable of implementing the decoding process on FPGA. The designed decoder reaches the expected throughput of 10 Gbps. A second contribution is about the optical uplink that implies hard input decoding in a satellite. Resulting constraints led us to rethink extended Gallager B algorithm. It made possible the develoment of a new architecture that manages the hard input decoding process efficiently while being compliant with space constraints, such as hardware complexity, heat dissipation and throughput (10 Gbps)
Jardak, Nabil. "Localisation en zones de non-couverture des systèmes de radionavigation par satellites à base de répéteurs GNSS". Evry, Institut national des télécommunications, 2008. http://www.theses.fr/2008TELE0027.
Texto completoThe indoor localisation systems are increasingly needed in supporting future Location Based Services (LBS). This thesis deals with the indoor positioning system based on GNSS repeaters. This system is based on the use of four repeaters which transmit the GNSS signals collected by an outdoor antenna indoors, in a time multiplexing mode. The positioning is based on the code phase jumps produced at the instant of the signal transition between two repeaters. This phase jumps mainly suffer from two error sources: thermal noise and multipath. Therefore, this thesis develops theoretical aspects of the system of repeaters and proposes innovative techniques to reduce the effect of the error sources on the phase jumps. The open loop technique was proposed to reduce the effect of thermal noise on the phase jumps based on the statistical properties of the noise. It implements an open code loop aided by the phase loop. Practical results showed a significant improvement in the phase jump measurement quality. The SMICL (Short Multipath Insensitive Code Loop) technique implements a code loop discriminator insensitive to multipath having relative delays lower than 0. 5 chip, typical of indoor environments. It dramatically improves the code phase measurements in the presence of multipath (maximum error between 1 and 2 m). Another multipath mitigation technique, the MIDLL (Multipath insensitive delay lock loop), is presented. The MIDLL is based on the fact that the code discriminator has an invariant point when it is suitably normalized. This technique outperforms the existing multipath mitigation techniques both in terms of simplicity of implementation in current receivers and precision (maximum error between 1 and 2 m, too). The SxPRCT (Subcarrier x PRN Reference Code Technique) filters medium and long multipaths by using a reference replica which is the product between the PRN code and a square subcarrier. The SxPRCT yields excellent results. The MIDLL and the SxPRCT were developed for the outdoor positioning using the GPS, as is the case of the SMICL but to a lesser extent. These techniques were adapted to the case of the system of repeaters. Moreover, the MIDLL has successfully been applied to the Galileo open service codes on E1. These techniques allow the repeaters based system to reach its theoretical accuracy namely indoor positioning in the range 2 meters
Barotto, Béatrice. "Introduction de paramètres stochastiques pour améliorer l'estimation des trajectoires d'un système dynamique par une méthode de moindres carrés : application à la détermination de l'orbite d'un satellite avec une précision centimétrique". Toulouse 3, 1995. http://www.theses.fr/1995TOU30196.
Texto completoBoutonnet, Arnaud. "Déploiement optimal contraint et robuste de satellites volant en formation invariante". Toulouse, ENSAE, 2003. http://www.theses.fr/2003ESAE0021.
Texto completoMétris, Gilles. "Théorie du mouvement du satellite artificiel : développement des équations du mouvement moyen : application à l'étude des longues périodes". Observatoire de Paris, 1991. http://www.theses.fr/1991OBSP0036.
Texto completoBertrand, Timothée. "Les sûretés dans le financement de projet des systèmes de télécommunications par satellites". Nice, 2003. http://www.theses.fr/2003NICE0011.
Texto completoToday the use of satellites has become essential for a host of activities. To put a satellite system in place requires extensive investments, secured by watertight loans. The space system (frequencies, orbital slot, code) is used in order to secure the lenders. These guarantees are not really adapted to this industry: indeed, how repossess an orbital satellite? More classical guarantees like collateral or mortgage on the real estate, the bank accounts, the commercial contracts, the insurance policies of the special purpose vehicle, are asked either to protect the lenders, as well as guarantees given by States, credit export agencies (COFACE), or international organizations (IFC). However, most industrials countries realized the necessity and the helpfulness of an international convention in this particular field. The UNIDROIT convention on international interest in mobile equipment and its preliminary draft protocol on space assets may bring renewed solutions
Thalmensy, Hervé Diaz Michel. "Émulation de réseaux au niveau IP pour l'expérimentation de services et protocoles de communication application aux réseaux satellites /". Toulouse : INP Toulouse, 2008. http://ethesis.inp-toulouse.fr/archive/00000701.
Texto completoDuplain, Éric. "Étude, conception et analyse des systèmes de commande pour un lanceur de satellites". Thesis, Université Laval, 2014. http://www.theses.ulaval.ca/2014/30625/30625.pdf.
Texto completoThis memoir’s main objective is to identify concepts of attitude control and open loop guidance to support the eventual development of a Canadian launcher, capable of orbiting microsatellites. A literature review of various systems involved in the stabilization of the launcher is presented. This review pinpointed the main difficulties met for attitude control of launch vehicles, as well as some possible solutions. Those are mainly the bending and sloshing of propellant. The attitude equations of motion for a rigid body launcher as a function of the steering angle of a nozzle are described. Controllers that stabilize and control the flexible launcher angular velocity and angular position on the six degrees of freedom DRDC Valcartier Simulink® simulator are devellopped. Finally, two techniques for guidance are explained and tested in presence of various perturbations.
Bonnet, Grégory. "Coopération au sein d'une constellation de satellites". Toulouse, ISAE, 2008. http://www.theses.fr/2008ESAE0006.
Texto completoBernier, Steve. "Conception et implantation basées sur des composants répartis d'une station terrestre virtuelle de communication satellite". Sherbrooke : Université de Sherbrooke, 2000.
Buscar texto completoLouembet, Christophe. "Génération de trajectoires optimales pour systèmes différentiellement platsApplication aux manoeuves d'attitude sur orbite". Bordeaux 1, 2007. http://www.theses.fr/2007BOR13429.
Texto completoThis thesis discusses the design of slew manoeuvers for Earth observation satellite. First, We show that the non linear model of reaction wheels actuated satellite satisfies the flatness property. Second, it is demonstrated that the main interest of path planning by flatness approach allows to solve the optimal control problem without the need of dynamics integration. By parameterizing the flat outputs by B-spline, we developed an non linear parametric problem that is solved with NLP solvers. To improve the computational quality of this methodology, we describe a convex subset where all constraints are satisfied. Using this subset, we can design a faster collocation-based path planner. The main drawback of this methodology is that constraints are only checked at collocation points. To overcome this drawback, we have developed a new trajectory generation scheme based on a B-spline positivity theorem that leads to efficient and tractable programming scheme using LMI techniques. Finally, we tested trajectories calculated by our flatness methodology in a CNES' Demeter simulator. We compared our results with the results from CNES trajectories generation tools. Our methodology improve the the optimal maneuvering time, the used control torque by diminishing the deflect to the initial trajectory and excitation of flexible structures
Barnault, Loïc. "Optimisation de la démodulation et du codage pour une communication sporadique de faible latence". Cergy-Pontoise, 2006. http://www.theses.fr/2006CERG0303.
Texto completoThe aim of this thesis consist in proposing a powerful communication system for satellite transmissions where the constraints put on the QoS and the spectral efficiency cannot be handled by existing systems. We work in a context of satellite communications where small packets are transmitted. Typically, the combinations code-modem which are proposed for spectral efficiencies in [0. 5,0. 8] are unbalanced in term of performance. The system we propose in this thesis is based on the 3PSK constellation which possesses a better demodulation capacity than BPSK or QPSK. In order to improve the cohabitation code-modem, we propose to associate a ternary burst modem with powerful ternary codes (TPC & LDPC). Finally, we show, after optimizations of the global system, that in the range of spectral efficiencies [0. 5,0. 8], our systems exhibit better performances than their binary counterparts
PEREIRA, TENEDORIO JOSE ANTONIO. "Teledetection en milieu periurbain : detection et localisation du changement de l'occupation du sol par integration des donnees-satellite spot hrv dans un systeme d'information geographique". Paris 12, 1998. http://www.theses.fr/1998PA120060.
Texto completoThis thesis presents a investigation which lead to a methodology proposal to locate and detect land cover changes in the urban fringe through the combination of spot hrv satellite image processing in a geographic information system (gis). Using multi-source data (satellite images and land cover maps) the discussed procedure allows to systematically determinate affectation zone changes in the urban fringe. The chosen technique relies on zone analysis applying six indexes: the panchromatic band, the vegetation index, the brightness index, the standard deviation, the recent mineralization index and the +nonwater; index. For each one of these indexes a stability limit was defined regarding the statistical parameters of the considered classes. The final result is materialised on a zone affectation change map
Bonnet, Jonathan. "Multi-criteria and multi-objective dynamic planning by self-adaptive multi-agent system, application to earth observation satellite constellations". Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30058/document.
Texto completoBuilding the best plan in product treatment, the best schedule to a building construction or the best route for a salesman in order to visit a maximum of cities in the time allowed while taking into account different constraints (economic, temporal, humans or meteorological ): in all of those variety of applications, optimizing the planning is a complex task including a huge number of heterogeneous entities in interaction, the strong dynamics, multiple contradictory objectives, etc. Mission planning for constellations of satellites is a major example: a lot of parameters and constraints, often antagonists must be integrated, leading to an important combinatorial search space. Currently, in Europe, plans are built on ground, just before the satellite is visible by the ground stations. Any request coming during the planning process must wait for the next period. Moreover, the complexity of this problem grows drastically: the number of constellations and satellites increases, as the number of daily requests. Current approaches have shown their limits. To overcome those drawbacks, new systems based on decentralization and distribution inherent to this problem, are needed. The adaptive multi-agent systems (AMAS) theory and especially the AMAS4Opt (AMAS For Optimization) model have shown their adequacy in complex optimization problems solving. The local and cooperative behavior of agents allows the system to self-adapt to highly dynamic environments and to quickly deliver adequate solutions. In this thesis, we focus on solving mission planning for satellite constellations using AMAS. Thus, we propose several enhancement for the agent models proposed by AMAS4Opt. Then, we design the ATLAS dynamic mission planning system. To validate ATLAS on several criteria, we rely on huge sets of heterogeneous data. Finally, this work is compared to an operational and standard system on real scenarios, highlighting the value of our system
Thalmensy, Hervé. "Émulation de réseaux au niveau IP pour l'expérimentation de services et protocoles de communication : application aux réseaux satellites". Toulouse, INPT, 2007. http://ethesis.inp-toulouse.fr/archive/00000701/.
Texto completoIn the context of protocol evaluation, several solutions are used : live tests, simulation and emulation. We focus on network emulation which allows the use of real applications or protocol implementations in a controllable environment. For this purpose, several characteristics (bandwidth, delay, losses) allow the real time reproduction of a target network behavior. In this thesis, we propose solutions based on metrology and simulation to reproduce in a flexible but efficient way the behavior of different network types such as the satellite one. We were involved in several projects (DIPCAST and EuQoS) for emulation of a satellite environment and we proposed an emulation architecture for emulation of a DVB-RCS satellite link. A methodology for quality of service network is also proposed
Vieira, Ricardo. "Synthèse et utilisation de nouveaux catalyseurs nanostructurés de décomposition de l'hydrazine pour des applications spaciales". Strasbourg 1, 2003. http://www.theses.fr/2003STR13093.
Texto completoDuring its lifespan, a satellite may undergo a variety of exterior influences that can eventually deviate it from its original orbit. As a result, it is necessary periodically to effectuate small corrections in the orbit of the satellite in order to maintain it on its desired course. This is done with the help of low-powered microthrust engines. Most satellites presently in use function using hydrazine catalytic decomposition microthrust engines with 30 to 40 wt. % iridium catalyst supported by stabilised alumina. We have developed by chemical vapordeposition a new material carbon nanofiber (CNF) base as an alternative to the traditional support. The procedure for this synthesis consists in growing CNF on a macroscopic support of a predefined nature (felt, foam, tissue, etc. ) and to form it by catalytic decomposition of ethane on nickel particles dispersed upon the surface of the support. We have chosen graphite as our precursor material, partly as a result of its elevated thermal conductivity and partly as a result of its total absence of porosity. This absence of porosity facilitates the access of reactive substances and at the same time does not impede the growth of the nanofibers. The NFC based composite was impregnated with 30 wt. % of iridium and submitted to a variety of thermal treatments. The overall performance of these catalysts has been evaluated in the hydrazine catalytic decomposition reaction, first in a micro-pilot plant under laboratory conditions, then in a 2 N microthruster under real-life conditions. The results obtained were compared with those of a commercial catalyst. The CNF based catalysts showed for better performance than the commercial catalyst from a standpoint of activity as from a standpoint of stability. In conclusion, we have demonstrated that this support is highly efficient in reaction needing fast mass and heat transfer due to its texture and it's thermal conductivity
Rebischung, Paul. "Can GNSS contribute to improving the ITRF definition ?" Observatoire de Paris, 2014. https://hal.science/tel-02095157.
Texto completoGlobal Navigation Satellite Systems (GNSS) play a fundamental role in the elaboration of the International Terrestrial Reference Frame (ITRF). However, GNSS have so far not proven able to reliably determine the terrestrial scale nor the location of the Earth’s center of mass (geocenter) and have thus not contributed to defining the ITRF scale nor its origin. The weak ability of GNSS to determine the terrestrial scale apart from conventional satellite phase center offsets is well understood. On the other hand, their inability to reliably monitor geocenter motion was so far not clearly explained. We investigated this question from the perspective of collinearity among the parameters of a least-squares regression. A generalized collinearity diagnosis was therefore developed and allows handling several peculiarities of the GNSS geocenter determination problem. It revealed that the determination of all three components of geocenter motion with GNSS suffers from serious collinearity issues due to the simultaneous estimation of epoch-wise station and satellite clock offsets and of tropospheric parameters in global GNSS data analyses. Several prospects were finally investigated in view of a possible future contribution of GNSS to the definition of the ITRF scale and origin: the antenna calibration of at least one GNSS satellite, the time invariability of the satellite phase center offsets, the simultaneous analysis of GNSS data collected by ground stations and low Earth orbiting satellites, the modelling of ultra-stable satellite clocks and the mitigation of orbit modelling errors
Magarotto, Eric. "Approche LMI pour la synthèse de correcteurs et d'observateurs : application aux systèmes spatiaux et bilinéaires". Nancy 1, 1999. http://www.theses.fr/1999NAN10033.
Texto completoThe growing power and popularity of LMI rnethods for control yield to consider the control design problem as a multiobjectives optimization one. The growing evolution of aerospace activities and the flexibility of its structures require more and more constraining robustness and performance specifications. In face of this growing complexity, we turn to the use of generical LMI-based algorithms, taking into account the poor conditionning of such systems. To treat this kind of specifications, we use a mixed H2/H[infini] output feedback control for both continuous and dis crete time linear systems. To facilitate its implementation, an arder reduction of the obtained controller is then realized. This thesis work was realized under a collaboration between Matra Marconi Space and the CNES, and applied to the line sight and attitude control of a telecommunication satellite
Deleu, Thibault. "Digital predistortion and equalization of the non-linear satellite communication channel". Doctoral thesis, Universite Libre de Bruxelles, 2014. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/209212.
Texto completoDoctorat en Sciences de l'ingénieur
info:eu-repo/semantics/nonPublished
Boada, Bauxell Josep. "Sur la commande de satellites à entrées saturantes". Toulouse, ISAE, 2010. https://tel.archives-ouvertes.fr/tel-00564267.
Texto completoJoannides, Marc. "Navigation intégrée d'un engin sous-marin remorqué. Filtrage non-linéaire des systèmes sans bruit d'observation et/ou mesures parfaites". Aix-Marseille 1, 1997. http://www.theses.fr/1997AIX11005.
Texto completoBénazéra, Emmanuel. "Diagnostic et reconfiguration basés sur des modèles hybrides concurrents : application aux satellites autonomes". Toulouse 3, 2003. http://www.theses.fr/2003TOU30105.
Texto completoMelachroinos, Stavros A. "Positionnement géodésique à haute fréquence de réseaux GNSS terrestres et marins". Observatoire de Paris (1667-....), 2007. https://hal.science/tel-02071426.
Texto completoThe surface deformations of the Earth’s crust and the sea-level variations measured by terrestrial or maritime GNSS networks are a subject that the CNES/GRGS team wanted to investigate thoroughly. In the first part, the main characteristics and differences of four global positioning systems that will constitute the future Global Navigation Satellite System of Systems are presented. In the second part, I concentrate in the definition of the basic geodetic components of GNSS used in positioning. In the third part, GINS scientific software package the basic tool used in this PhD study is presented. Updated modifications implemented for the needs of my research are overseen. Then validations tests of the modifications on the level of precise orbit determination (for GPS and GIOVE-A) and positioning are presented. In the fourth part, the main study of ocean tide loading – OTL in a complex coastal area that of Brittany, in France is presented. The implemented method aims to use a dedicated dense GPS network in order to evaluate/validate the performances of ocean tide models in the region. The impact of OTL on tropospheric parameters, the datum stability used to align the GNSS solution and the aliasing affects on the campaign stations’ time-series of unmodeled vertical displacement are analyzed. In the final and last part, the preliminary results of a GPS kinematic data set designated to cross compare and validate altimetric and oceanographic observations of the Antarctic Circumpolar Current are analyzed
Rabemanantsoa, Josh. "Conception d'antennes hélices quadrifilaires imprimées compactes et bibandes pour les systèmes de communication par satellite". Rennes 1, 2011. http://www.theses.fr/2011REN1S049.
Texto completoThe increasing availability of navigation systems like GPS (Global Positioning System) was used to flood the world market by a large number of new receivers combining good performance, small size and low power consumption. In addition, deployment of new European radio navigation system, Galileo, and its combination with GPS will allow the implementation of application more reliable high accuracy. Navigation systems generally require multi-band antennas compact circular polarization performance. Hemispherical coverage is also desirable for satellite communications in general and navigation in particular because the terminal must receive signals from any relay or satellite. Printed Quadrifilar Helical Antennas (PQHA), improved Resonant Quadrifilar Helical Antennas (RQHA) are attractive candidates for these satellite systems through their radio performance fulfilling the conditions mentioned above. However, two major handicaps that need to be remedied, limit the use of these antennas in mobile devices including : size (especially height) and the single-band operation. In this thesis, several antennas topologies HQI compact dual-band or multi-band are presented. They provide reports of resonant frequencies with adjustable rate reduction of up to 73 %. The proposed antennas allow stable radiation patterns at different frequencies of operation of GPS, L1/L2 or L1/L5 with a good compromise between adaptation, effectivenesse and quality of polarization
Caouren, Natacha. "Modélisation et prédiction des phénomènes de scintillation perturbateurs des systèmes radioélectriques par satellite". Rennes 1, 2001. http://www.theses.fr/2001REN10122.
Texto completoZehana, Mustapha. "Connaissances structurelles et interprétation d'images satellitaires". Toulouse 3, 1995. http://www.theses.fr/1995TOU30035.
Texto completoCoulot, David. "Télémétrie laser sur satellites et combinaison de techniques géodésiques : contributions aux systèmes de référence terrestres et applications". Phd thesis, Observatoire de Paris, 2005. http://tel.archives-ouvertes.fr/tel-00069016.
Texto completoCoulot, David. "Télémétrie laser sur satellites et combinaison de techniques géodésiques : contributions aux systèmes de référence terrestres et applications". Phd thesis, Observatoire de Paris (1667-....), 2005. https://theses.hal.science/tel-00069016.
Texto completoBeaumet, Grégory. "Planification continue pour la conduite d'un satellite d'observation agile autonome". Toulouse, ISAE, 2008. http://www.theses.fr/2008ESAE0003.
Texto completoHenniquau, Dimitri. "Conception d’une interface fonctionnelle permettant la communication de neurones artificiels et biologiques pour des applications dans le domaine des neurosciences". Thesis, Université de Lille (2018-2021), 2021. http://www.theses.fr/2021LILUN032.
Texto completoNeuromorphic engineering is an exciting emerging new field, which combines skills in electronics, mathematics, computer sciences and biomorphic engineering with the aim of developing artificial neuronal networks capable of reproducing the brain’s data processing. Thus, neuromorphic systems not only offer more effective and energy efficient solutions than current data processing technologies, but also set the bases for developing novel original therapeutic strategies in the context of pathological brain dysfunctions. The research group Circuits Systèmes Applications des Micro-ondes (CSAM) of the Institute for Electronics, Microelectronics and Nanotechnologies (IEMN) in Lille, in which this thesis work was carried out, has contributed to the generation of such neuromorphic systems by developing a toolbox constituted of artificial neurons and synapses. In order to implement neuromorphic engineering in the therapeutic arsenal for treating neurologic disorders, we need to interface living and artificial neurons to ensure real communication between these different components. In this context and using the original tools developed by the CSAM group, the main goal of this thesis work was to design and produce a functional interface allowing a bidirectional communication loop to be established between living and artificial neurons. These artificial neurons have been developed by the CSAM group using CMOS technology and are able to emit biomimetic electrical signals. Living neurons were obtained from differentiated PC-12 cells. A first step in this work consisted in modeling and simulating this interface between artificial and living neurons; a second part of the thesis was dedicated to the fabrication and characterization of neurobiohybrid interfaces, and to the growth and characterization of living neurons before studying their capacities to communicate with artificial neurons. First, a model of neuronal membrane representing a living neuron interfaced with a metallic planar electrode has been developed. We thus showed that it is possible to excite neurons using biomimetic signals produced by artificial neurons while maintaining a low excitation voltage. Low voltage excitation would improve energy efficiency of neurobiohybrid systems integrating artificial neurons and reduce the impact of harmful electrical signals on living neurons. Then, the neurobiohybrid interfacing living and artificial neurons has been designed and produced. The results obtained by experimental characterization of this interface validate the approach consisting in exciting living neurons through a metallic planar electrode. Finally, living neurons from PC-12 cells were grown and differentiated directly onto neurobiohybrids. Then, an experimental proof of the ability of biomimetic electrical signals to excite living neurons was obtained using calcium imaging. To conclude, the work presented in this manuscript clearly establishes a proof of concept for the excitation of living neurons using a biomimetic signal in our experimental conditions and thus substantiates the first part of the bidirectional communication loop between artificial neurons and living neurons
Laderrière, Cyril. "Etude et caractérisation d'un couplage entre signaux Ultra Large Bande et signaux GNSS pour la localisation". Valenciennes, 2009. http://ged.univ-valenciennes.fr/nuxeo/site/esupversions/a87e0e71-f3fa-4260-95f5-3d146d819b81.
Texto completoDespite last generation Navigation Satellite Systems receiver (GNSS) outstanding sensitivity enhancements, inherent GNSS system margins do not appear sufficient for proper operation down to deep indoor environments. In this framework, pervasive localization issues with seamless transition outdoors/indoors and high demanding accuracy is addressed by associating GNSS with the emerging radio technology named Ultra Wide-Band (UWB). Reminding both technologies involve their signals to be synchronized for multi-lateration purposes, this thesis assesses the opportunity to retrieve GNSS clock outdoors, to synchronize UWB localization signals indoors. Within the scope of a localization application, the UWB radio transmission design proposal is first optimized, taking into account the indoor propagation specificities, then considering regulatory requirements for unlicensed use of UWB in the 3,1 to 10,6 GHz range. The relevancy of such a coupling is then experimentally addressed, first, demonstrating how the GNSS clock can be locally recovered outdoors; then, evaluating the UWB receiver ability to recover this synchronization in an evolving selective fading indoor channel impacted, for instance, by moving people in the environment. Results of such a coupling characterization between GNSS and UWB signals are finally highlighted in a localization perspective, contributing to the system simulation and modelling
Tra, Ferdinand. "Contrôle d'admission des connexions pour les systèmes de télécommunications par satellite avec des liaisons physiques adaptatives". Toulouse, ISAE, 2008. http://www.theses.fr/2008ESAE0021.
Texto completoChicoisne, Guillaume. "Dialogue entre agents naturels et agents artificiels : une application aux communautés virtuelles". Phd thesis, Grenoble INPG, 2002. http://tel.archives-ouvertes.fr/tel-00004385.
Texto completoNainer, Carlo. "In-Orbit Data Driven Parameter Estimation for Attitude Control of Satellites". Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0058.
Texto completoThe system identification for satellite attitude control is investigated in this thesis. Several parameter estimation algorithms are developed and adapted to the different types of sensor (gyroscope or star tracker). These algorithms allow to estimate, from the telemetry data, the satellite inertia matrix as well as the actuator alignments. For these estimation algorithms, an instrumental variable approach is considered. Filters are designed in order to significantly improve the accuracy and precision of the estimates, even in presence of sensor noise and disturbance torques. The performances of the proposed algorithms are analyzed and validated via Monte Carlo simulations using data from a high-fidelity simulator from CNES. The second main contribution concerns the optimization of maneuvers to improve the information content in the data, while respecting the physical constraints of the satellite. The effectiveness of the generated trajectory is evaluated both via Monte Carlo simulations and through real experiments in a zero-gravity environment
Trouillard, Géraldine. "Contribution à l'étude des phénomènes électromagnétiques liés aux futurs systèmes mobiles de réception hertzienne à bord des véhicules automobiles : Conception, réalisation et tests des antennes correspondantes". Limoges, 2003. http://aurore.unilim.fr/theses/nxfile/default/db284277-0e67-4cb1-8d44-ef3984dad323/blobholder:0/2003LIMO0034.pdf.
Texto completoThis thesis managed with SCE-MAG (FIAMM group^), deals with Satellite Digital Audio-Radio Service and Particularly XM Radio systems which are using terrestrial and satellite broadcasting technologies around 2,34 GHz ans are dedicated to car users. Ti fit XM's requirements, a circularly polarized four patches array for satellite reception has been simulated thanks to a strong digital tool (FDTD) and then realized and measured with experimental equipment. A second study has been done concerning new specifications combining XM and Sirius systems leading to the design of two new antennas using printed technology. To conclude, a linearly polarized antenna (Wire-patch) for the terrestrial reception has been integrated with the circularly polarized antennas