Teses / dissertações sobre o tema "Focalisation spatiale de données"
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Molineaux, Guylian. "Spatial Data Focusing for High-Precision Wireless Geocasting : Theoretical System Design and Practical Proof of Concept". Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS491.
Texto completo da fonteThis thesis investigates spatial data focusing (SDF) as a means of performing wireless physical-layer geocasting, i.e. location-based multicasting or geographically-confined broadcasting. This novel approach can aid in providing location-based services and messaging to large groups of mobile devices that exist in emerging internet-of-things frameworks for smart cities, industries, healthcare, etc., providing users with information that is related or contextualized to their geographical location. It addresses and avoids privacy concerns that exist in conventional location-based services, where users are required to disclose their location. In addition, it overcomes node self-localization requirements and the challenging balance between overhead, scalability, and delivery rate that exist in network-layer geocast routing algorithms. Most importantly, it succeeds in increasing precision, reducing array size, and minimizing complexity - the most crucial conditions in making physical-layer geocasting an attractive scheme - compared to conventional beamforming-based power focusing approaches. Within the SDF framework, it additionally addresses two fundamental shortcomings. That is, (i) a limitation to focusing in the angular domain only or, equivalently, the inability for range-domain focusing and (ii) a severe sensitivity to multipath propagation that jeopardizes correct operation outside hypothetical free space channels. They are overcome by designing two novel SDF architectures that exploit multi-frequency transmission resources in an orthogonal frequency-division multiplexing (OFDM) and frequency diverse array (FDA) framework. Additionally, an experimental proof-of-concept SDF architecture is developed that demonstrates its practical achievability as a novel geocasting technique
Odhiambo, Michael Derrick. "Spatial data focusing using direct sequence spread spectrum modulation". Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS060.
Texto completo da fonteThis work proposes the implementation of Spatial Data Focusing (SDF) using spread spectrum techniques. SDF was recently proposed as a candidate alternative to classical power focusing schemes in wireless geocasting applications. Unlike power focusing approaches where radiated power is directed to a defined direction, in SDF, it is the data to be transmitted that is processed in such a manner that it can only be decoded at a predefined location. This work exploits the dual orthogonality due to classical quadrature components and orthogonal Gold spreading sequences to design the IQ and spread spectrum based spatial data focusing (DSSS-SDF-IQ) scheme. It is demonstrated that SDF attains better spatial selectivity than classical power focusing for a given antenna array size. The robustness of the proposed scheme is subsequently demonstrated by implementing it over a classical Urban Canyon 6-ray multipath channel model, where it is shown that the scheme can exhibit beamwidth as narrow as 1 degree with only a 4-antenna array. In SDF, the beamwidth is defined as the area within which data can be decoded as opposed to classical half power beamwidth. Chapter 1 introduces the concept of geocasting. Chapter 2 reviews the different techniques that enable directional capabilities on base stations. Chapter 3 introduces the principles of direct sequence spread spectrum based SDF. Chapter 4 investigates the influence of multipath channel on DSSS-SDF scheme. For all the cases studied above, relevant simulations are implemeneted to validate the discussions. Chapter 5 summarizes the work with a conclusion and perspective on possible future research directions
Gharbi, Zied. "Contribution à l’économétrie spatiale et l’analyse de données fonctionnelles". Thesis, Lille 1, 2019. http://www.theses.fr/2019LIL1A012/document.
Texto completo da fonteThis thesis covers two important fields of research in inferential statistics, namely spatial econometrics and functional data analysis. More precisely, we have focused on the analysis of real spatial or spatio-functional data by extending certain inferential methods to take into account a possible spatial dependence. We first considered the estimation of a spatial autoregressive model (SAR) with a functional dependent variable and a real response variable using observations on a given geographical unit. This is a regression model with the specificity that each observation of the independent variable collected in a geographical location depends on observations of the same variable in neighboring locations. This relationship between neighbors is generally measured by a square matrix called the spatial weighting matrix, which measures the interaction effect between neighboring spatial units. This matrix is assumed to be exogenous, i.e. the metric used to construct it does not depend on the explanatory variable. The contribution of this thesis to this model lies in the fact that the explanatory variable is of a functional nature, with values in a space of infinite dimension. Our estimation methodology is based on a dimension reduction of the functional explanatory variable through functional principal component analysis followed by maximization of the truncated likelihood of the model. Asymptotic properties of the estimators, illustrations of the performance of the estimators via a Monte Carlo study and an application to real environmental data were considered. In the second contribution, we use the functional SAR model studied in the first part by considering an endogenous structure of the spatial weighting matrix. Instead of using a geographical criterion to calculate the dependencies between neighboring locations, we calculate them via an endogenous process, i.e. one that depends on explanatory variables. We apply the same two-step estimation approach described above and study the performance of the proposed estimator for finite or infinite-tending samples. In the third part of this thesis we focus on heteroskedasticity in partially linear models for real exogenous variables and binary response variable. We propose a spatial Probit model containing a non-parametric part. Spatial dependence is introduced at the level of errors (perturbations) of the model considered. The estimation of the parametric and non-parametric parts of the model is recursive and consists of first setting the parametric parameters and estimating the non-parametric part using the weighted likelihood method and then using the latter estimate to construct a likelihood profile to estimate the parametric part. The performance of the proposed method is investigated via a Monte-Carlo study. An empirical study on the relationship between economic growth and environmental quality in Sweden using some spatial econometric tools finishes the document
Boutin, Denis. "Outils de mise à jour de données distribuées application aux données à référence spatiale". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1999. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape7/PQDD_0016/MQ56871.pdf.
Texto completo da fonteJouini, Khaled. "Optimisation de la localité spatiale des données temporelles et multiversions". Paris 9, 2008. https://bu.dauphine.psl.eu/fileviewer/index.php?doc=2008PA090016.
Texto completo da fonteThe efficient management of temporal and multiversion data is crucial for many traditional and emerging database applications. A major performance bottleneck for database systems is the memory hierarchy. One of the main means for optimizing the utilization of the memory hierarchy is to optimize data spatial locality, i. E. To put contiguously data that are likely to be read simultaneously. The problem studied in this thesis is to optimize temporal and multiversion data spatial locality at all levels of the memory hierarchy, using index structures and storage policies. In particular, this thesis proposes a cost model, the steady state analysis, allowing an accurate estimation of the performance of different index structures. The analysis provides database designers tools allowing them to determine the most suitable index structure, for given data and application characteristics. This thesis also studies the impact of version redundancy on L2 cache utilization. It proposes two storage models which, in contrast with the standard storage models, avoid version redundancy and optimize L2 cache and main memory bandwidth utilization
Zenasni, Sarah. "Extraction d'information spatiale à partir de données textuelles non-standards". Thesis, Montpellier, 2018. http://www.theses.fr/2018MONTS076/document.
Texto completo da fonteThe extraction of spatial information from textual data has become an important research topic in the field of Natural Language Processing (NLP). It meets a crucial need in the information society, in particular, to improve the efficiency of Information Retrieval (IR) systems for different applications (tourism, spatial planning, opinion analysis, etc.). Such systems require a detailed analysis of the spatial information contained in the available textual data (web pages, e-mails, tweets, SMS, etc.). However, the multitude and the variety of these data, as well as the regular emergence of new forms of writing, make difficult the automatic extraction of information from such corpora.To meet these challenges, we propose, in this thesis, new text mining approaches allowing the automatic identification of variants of spatial entities and relations from textual data of the mediated communication. These approaches are based on three main contributions that provide intelligent navigation methods. Our first contribution focuses on the problem of recognition and identification of spatial entities from short messages corpora (SMS, tweets) characterized by weakly standardized modes of writing. The second contribution is dedicated to the identification of new forms/variants of spatial relations from these specific corpora. Finally, the third contribution concerns the identification of the semantic relations associated withthe textual spatial information
Ahmed, Mohamed Salem. "Contribution à la statistique spatiale et l'analyse de données fonctionnelles". Thesis, Lille 3, 2017. http://www.theses.fr/2017LIL30047/document.
Texto completo da fonteThis thesis is about statistical inference for spatial and/or functional data. Indeed, weare interested in estimation of unknown parameters of some models from random or nonrandom(stratified) samples composed of independent or spatially dependent variables.The specificity of the proposed methods lies in the fact that they take into considerationthe considered sample nature (stratified or spatial sample).We begin by studying data valued in a space of infinite dimension or so-called ”functionaldata”. First, we study a functional binary choice model explored in a case-controlor choice-based sample design context. The specificity of this study is that the proposedmethod takes into account the sampling scheme. We describe a conditional likelihoodfunction under the sampling distribution and a reduction of dimension strategy to definea feasible conditional maximum likelihood estimator of the model. Asymptotic propertiesof the proposed estimates as well as their application to simulated and real data are given.Secondly, we explore a functional linear autoregressive spatial model whose particularityis on the functional nature of the explanatory variable and the structure of the spatialdependence. The estimation procedure consists of reducing the infinite dimension of thefunctional variable and maximizing a quasi-likelihood function. We establish the consistencyand asymptotic normality of the estimator. The usefulness of the methodology isillustrated via simulations and an application to some real data.In the second part of the thesis, we address some estimation and prediction problemsof real random spatial variables. We start by generalizing the k-nearest neighbors method,namely k-NN, to predict a spatial process at non-observed locations using some covariates.The specificity of the proposed k-NN predictor lies in the fact that it is flexible and allowsa number of heterogeneity in the covariate. We establish the almost complete convergencewith rates of the spatial predictor whose performance is ensured by an application oversimulated and environmental data. In addition, we generalize the partially linear probitmodel of independent data to the spatial case. We use a linear process for disturbancesallowing various spatial dependencies and propose a semiparametric estimation approachbased on weighted likelihood and generalized method of moments methods. We establishthe consistency and asymptotic distribution of the proposed estimators and investigate thefinite sample performance of the estimators on simulated data. We end by an applicationof spatial binary choice models to identify UADT (Upper aerodigestive tract) cancer riskfactors in the north region of France which displays the highest rates of such cancerincidence and mortality of the country
Pasqua, Roberto. "Inférence et modèles de données personnelles : mobilité sociale, proximité spatiale". Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30195/document.
Texto completo da fonteThe wide diffusion of smart portable devices allows the collection of a big amount of data concerning the activities of users from mobile apps. We focus our attention on location data, i.e. mobility traces, of a set of users in a crowd. Data collected from these mobile systems are studied following two axies: - Mobility models are used to simulate the behavior of users to develop opportunistic forwarding algorithms. We compare real and synthetic mobility traces to show the distance between the reality and the models. - Information on mobility may endanger the privacy of users. We analyze the impact of such information on privacy of users. The main contributions are: - We analyze the spatial and social properties of human motion from real traces collected by a highly accurate experimental localization system. - We compare the real traces with synthetic mobility traces generated from seven popular mobility models - We provide an inference algorithm based on co-location of users and we show its efficiency on different datasets. - We quantify the effect of probabilistic co-location information by means of a novel co-location attack
Engélinus, Jonathan. "Elaboration d'un moteur de traitement des données spatiales massives vectorielles optimisant l'indexation spatiale". Master's thesis, Université Laval, 2017. http://hdl.handle.net/20.500.11794/28046.
Texto completo da fonteBig data are in the midst of many scientific and economic issues. Furthermore their volume is continuously increasing. As a result, the need for management and processing solutions has become critical. Unfortunately, while most of these data have a vectorial spatial component, almost none of the current systems are able to manage it. In addition, the few systems who try either do not respect the ISO standards and OGC specifications or show poor performances. The aim of this research was then to determine how to manage the vectorial massive data more completely and efficiently. The objective was to find a scalable way of indexing them, ensuring their compatibility with ISO-19125 and its extensions, and making them accessible from GIS. The result is the Elcano system. It is an extension of the massive data management system Spark which provides increased performance compared to current market solutions.
Hardy, Emilie. "Procédures expérimentales et traitement des données associées pour la mission spatiale MICROSCOPE". Observatoire de Paris (1667-....), 2013. https://hal.science/tel-02095140.
Texto completo da fonteThe MICROSCOPE space mission aims at testing the Equivalence Principle with an accuracy of 1E-15. The instrument will be embarked on board a drag-free microsatellite, and consists in a differential electrostatic accelerometer composed of two test masses submitted to the same gravitional field but made of different material. The accelerations applied to the masses to maintain them relatively motionless are measured and will demonstrate a violation of the universality of free fall if found unequal. The accuracy of the measurement exploited for the test is limited by our a priori knowledge of the instrument physical parameters. An in-orbit calibration is needed to finely characterize them in order to correct the measurement. Appropriate calibration procedures have been determined. In order to validate their performances, they have been implemented in a software tool dedicated to the calibration sessions which simulates the instrument, the satellite and its environment. Other pertubations must be considered during the data analysis : numerical effects arise from the finite time span of the measurement. These effects have been evaluated and a procedure has been determined to process the data with minimal numerical perturbations, in a nominal situation as well as in the case of missing data, which may amplify these effects. Finally, a simulator has been developed for the entire mission scenario in order to study the association of instrumental and numerical simulations. This tool enables to simulate both the calibration sessions and the sessions for the test of the Equivalence Principle, and is therefore used to validate the protocol of measurement correction and analysis
Fize, Jacques. "Mise en correspondance de données textuelles hétérogènes fondée sur la dimension spatiale". Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTS099.
Texto completo da fonteWith the rise of Big Data, the processing of Volume, Velocity (growth and evolution) and data Variety concentrates the efforts of communities to exploit these new resources. These new resources have become so important that they are considered the new "black gold". In recent years, volume and velocity have been aspects of the data that are controlled, unlike variety, which remains a major challenge. This thesis presents two contributions in the field of heterogeneous data matching, with a focus on the spatial dimension.The first contribution is based on a two-step process for matching heterogeneous textual data: georepresentation and geomatching. In the first phase, we propose to represent the spatial dimension of each document in a corpus through a dedicated structure, the Spatial Textual Representation (STR). This graph representation is composed of the spatial entities identified in the document, as well as the spatial relationships they maintain. To identify the spatial entities of a document and their spatial relationships, we propose a dedicated resource, called Geodict. The second phase, geomatching, computes the similarity between the generated representations (STR). Based on the nature of the STR structure (i.e. graph), different algorithms of graph matching were studied. To assess the relevance of a match, we propose a set of 6 criteria based on a definition of the spatial similarity between two documents.The second contribution is based on the thematic dimension of textual data and its participation in the spatial matching process. We propose to identify the themes that appear in the same contextual window as certain spatial entities. The objective is to induce some of the implicit spatial similarities between the documents. To do this, we propose to extend the structure of STR using two concepts: the thematic entity and the thematic relationship. The thematic entity represents a concept specific to a particular field (agronomic, medical) and represented according to different spellings present in a terminology resource, in this case a vocabulary. A thematic relationship links a spatial entity to a thematic entity if they appear in the same window. The selected vocabularies and the new form of STR integrating the thematic dimension are evaluated according to their coverage on the studied corpora, as well as their contributions to the heterogeneous textual matching process on the spatial dimension
Claramunt, Christophe. "Un modèle de vue spatiale pour une représentation flexible de données géographiques". Dijon, 1998. https://hal.archives-ouvertes.fr/tel-01275819.
Texto completo da fonteMedeiros, Moreira Daniel. "Apport des données de géodésie spatiale pour l'étude du bassin hydrologique amazonien". Thesis, Toulouse 3, 2016. http://www.theses.fr/2016TOU30372/document.
Texto completo da fonteThis study is based on the evaluation of the use of geodetic data for monitoring and modeling of water resources of the Amazon basin, assuming the hypothesis that the principles of Geodesy allow to expand the set of observational hydrological information with respect to quantity and quality in order to make them available for this important river basin. The main objective was to establish a protocol to level the gauged stations of the conventional network and to get steepness profiles for the water line of the main Amazon rivers on an unprecedented scale. Accordingly, we used GNSS data processing procedure to measure the accuracy of the precise point positioning (PPP) technique, which allowed to investigate its efficiency when compared to the classical techniques and their recent innovations. In addition, in order to achieve better accuracy in geodetic surveys, the effects of hydrologic loads were also measured by means of the use of data series acquired through GRACE satellite, coming from four different analysis centers (CSR, JPL, GFZ and GRGS) jointly with the hydrologic load correction model HYDL. The results showed that these sources of information offered support in correcting hydrologic loads of 18 GNSS stations existing in the Amazon basin. In particular, it was found that the use of data from leveled gauged stations and water line profiles defined by GNSS receivers allowed the evaluation of the accuracy of altimetry data in such an innovative and rigorous manner as derived from Jason-2, ENVISAT and ICESAT satellites highlighting their potential and widespread use in hydraulic-hydrological studies of monitoring and modeling on various spatiotemporal scales
Fressengeas, Nicolas. "ETUDE EXPERIMENTALE ET THEORIQUE DE L'AUTO-FOCALISATION D'UN FAISCEAU LASER EN MILIEU PHOTOREFRACTIF : CONVERGENCES SPATIALE ET TEMPORELLE VERS UN SOLITON". Phd thesis, Université de Metz, 1997. http://tel.archives-ouvertes.fr/tel-00520187.
Texto completo da fonteFressengeas, Nicolas André Kugel Godefroy. "ETUDE EXPERIMENTALE ET THEORIQUE DE L'AUTO-FOCALISATION D'UN FAISCEAU LASER EN MILIEU PHOTOREFRACTIF : CONVERGENCES SPATIALE ET TEMPORELLE VERS UN SOLITON /". [S.l.] : [s.n.], 1997. ftp://ftp.scd.univ-metz.fr/pub/Theses/1997/Fressengeas.Nicolas.SMZ9724.pdf.
Texto completo da fonteChulyadyo, Rajani. "Un nouvel horizon pour la recommandation : intégration de la dimension spatiale dans l'aide à la décision". Thesis, Nantes, 2016. http://www.theses.fr/2016NANT4012/document.
Texto completo da fonteNowadays it is very common to represent a system in terms of relationships between objects. One of the common applications of such relational data is Recommender System (RS), which usually deals with the relationships between users and items. Probabilistic Relational Models (PRMs) can be a good choice for modeling probabilistic dependencies between such objects. A growing trend in recommender systems is to add spatial dimensions to these objects, and make recommendations considering the location of users and/or items. This thesis deals with the (not much explored) intersection of three related fields – Probabilistic Relational Models (a method to learn probabilistic models from relational data), spatial data (often used in relational settings), and recommender systems (which deal with relational data). The first contribution of this thesis deals with the overlapping of PRM and recommender systems. We have proposed a PRM-based personalized recommender system that is capable of making recommendations from user queries in cold-start systems without user profiles. Our second contribution addresses the problem of integrating spatial information into a PRM
Rahal, Mohamed Cherif. "Classification ascendante spatiale : nouveaux algorithmes et aide à l'interprétation". Paris 9, 2010. https://portail.bu.dauphine.fr/fileviewer/index.php?doc=2010PA090003.
Texto completo da fonteRosa, Domingos João Miguel. "Modes de variabilité géomagnétiques et de météo spatiale à partir des données satellites". Thesis, Université Grenoble Alpes (ComUE), 2018. http://www.theses.fr/2018GREAU007/document.
Texto completo da fonteThis work focus on the study of the South Atlantic Anomaly (SAA) of the main magnetic field from satellite data, aiming at identifying different sources of variability. This is done by first applying the Principal Component Analysis (PCA) method to particle flux and dark noise data and then to Virtual Observatories (VOs) time series constructed from satellite magnetic records. Particle flux data are provided by three POES NOAA satellites (10, 12 and 15) and the Jason-2 satellite. Dark noise data, which can be interpreted as a proxy to particle flux, are provided by the CALIOP lidar onboard the CALIPSO satellite. The magnetic field information is used in the form of time series for VOs, which were computed from both CHAMP and Swarm data as two separate datasets. The two different groups of data provide different views of the South Atlantic Anomaly. Applying PCA to particle flux data on the SAA produces interesting modes that can be related with specific physical processes involved with the anomaly. The main sources that drive these modes are the Earth’s magnetic field and the Sun. The Sun’s 11-year cycle is a well-known quasi-period of solar activity. This work shows how it clearly affects the evolution of the energetic particles trapped in the inner Van Allen belt, by modulating both their total number and their distribution among different L-shells. The way particles become trapped and move near-Earth is also dictated by the main magnetic field geometry and intensity and so a good understanding of its variation allows for a better description of the evolution of these particles. The main magnetic field, with origin in the Earth’s liquid core, is responsible for a slow drift of the anomaly, associated to the Westward drift of several features of the main field. Changing the frame of reference to that of the eccentric dipole, we were able to identify two separate modes associated with the variability of the solar activity. On longer time-scales, we also observed a linear trend in the spatial evolution of the particle flux. A global analysis of variability modes of the Earth’s magnetic field has not been often addressed. This study also contributes to fill this gap. By decomposing satellite records of the magnetic field into PCA modes, we retrieved modes of internal origin and modes with large external contributions, with no a-priori considerations. An annual signal has been identified and associated with mainly external sources. It exhibits an interesting geometry dominated by a zonal quadrupolar geometry. As for the internal source, three separate modes were obtained from the longest time series analysed. The first of these modes explains most of the variability of the field and represents the mean secular variation. It is closely modelled by an eccentric tilted dipole moving away from the Earth’s center and toward under East Asia. As this study shows, this simple model turns out to be a useful tool that can be used both on regional studies of the SAA and on global studies of the geomagnetic field
Pellier, Karine. "La dynamique structurelle et spatiale des systèmes de brevets". Thesis, Montpellier 1, 2010. http://www.theses.fr/2010MON10025.
Texto completo da fonteAt the behest of Schumpeter's seminal works, innovation is now positioned at the heart of economic analysis. However, since these pioneering works, not enough innovation studies have been devoted to the uses of patent over time. Starting from this assertion, the present thesis aims first and foremost at providing - in addition to good quality empirical information and new statistical series - a new interpretation of patents in their structural and spatial dimensions, based on a cliometric approach. Our first contribution is to present the organisation of a new database on the evolution over a long period of time of patents in 40 countries from the XVIIth century up to 1945 and in over 150 countries from 1945 to the present time. We show in a second step that rare but nevertheless significant events conditioned the heartbeat of the economic history of patents. Wars, the promulgation of laws, the opening or closing of offices, but also purely statistical effects standardized over the long term the existence of patent systems through the application and granting of the series under study. Furthermore we determine the periodicity of our patent series using a spectral and co-spectral analysis. Finally we propose a more contemporary insight - in terms of convergence - into structural and more specifically spatial dynamics at work in the European countries patent systems
Doukari, Omar. "Changement de croyances local et application à l'information spatiale". Aix-Marseille 1, 2010. http://www.theses.fr/2010AIX11002.
Texto completo da fonteWhen facing uncertain, incomplete and inaccurate information, we need a belief change operation in order to manage the belief evolution in presence of new information. The problem of belief change, in general, is known as a NP-difficult one, and there does not exist an efficient algorithm that can process huge amount of data. To circumvent this problem, we are interested in local belief change operations, namely local belief revision, local belief contraction, and local belief expansion operations. A new model -the C-structure model- for belief representation and local belief revision is proposed. A C-structure represents a thematic view of the overall knowledge of an agent with a good understanding of the interactions between topics. Hence, it provides the agent with an extra-structure, which helps circumscribing the relevant part of beliefs during a revision operation. Then, four local belief change operators are defined, based on the C-structure model : one for local expansion, one for local contraction, and two for local belief revision, internal and external ones. The contraction and revision operators are proved sound and complete by comparing them to traditional non local belief change operators. Local belief revision based on the C-structure model is characterized semantically ; first, in the special case of fully overlapping theories, then in the general case of arbitrary theories. Finally, the spatial information is considered : it provides an interesting application to the C-structure model and the associated revision operations. A new model -the G-structure model- is defined. Then, a new local belief revision approach, based on the G-structure model, is proposed and compared to the REM approach which is based on the Reiter algorithm for diagnosis
Legrand, Raphaël. "Utilisation des déformations spatiales en assimilation de données". Thesis, Toulouse 3, 2015. http://www.theses.fr/2015TOU30372/document.
Texto completo da fonteData assimilation provides initial conditions (the analysis) for the model from two sources of information: the available observations and a short term forecast (the background). The relative weights of both sources depend on the chosen error model. Usually, background errors are modeled as additive amplitude errors and, following a probabilistic approach, their probability density function (PDF) are modeled as Gaussians, specified with a zero mean and a covariance matrix B. For this PhD, the tackled issue are the lack of flow dependency of B and the non-Gaussianity (NG) frequently arising in numerical weather prediction (NWP), especially in case of displacement error. Using spatial deformation methods and ensemble of forecasts generated from an ensemble of data (EDA), the aim of this work is to refine the model of background error correlations, and to correct displacement errors as a possible way to get closer to the Gaussian hypothesis. A first part of this work is to improve the B modeling, by accounting objectively for the anisotropy of the background error correlations thanks to spatial deformation, which is statistically estimated from an EDA. This statistical method (ST) is applied to a real dataset of ARPEGE, the global model at Météo-France. The ST is compared to an other spatial warping method, the geostrophic transform (GT), and their efficiency are quantified by an anisotropy index. Results show a better efficiency of the ST than the GT, with a more systematic accounting of the anisotropy of the spatial background correlations. The second part of this work is a documentation of the NG for the background errors of AROME, the convective scale model at Météo-France. Distributions are diagnosed from an EDA, and their Gaussianity is quantified with a statistical index only based on two shape parameters, skewness and kurtosis. The diagnosed NG is spatially and temporally dependent, with large similarities between meteorological and NG structures. Links with nonlinear processes, linked for example to cloud covering, are observed. Diagnostics also show that the analysis step is largely decreasing the observed NG of the background, and that the most non-Gaussian variables in control space are vorticity and divergence. Since, a possible reason of the NG is the displacement errors, the third part of this PhD work aims at getting insight in the documentation of this alternative error model. First, a quasi-linear, quasi-Gaussian and multi-scale method, inspired from optical flow estimation methods, is derived. It has been tested on ideal case and on real cases based on AROME forecast fields. Future works may be, first, a statistical estimation of the main parameters characterizing this kind of error, and second, the use of this algorithm to correct displacement error upstream of the additive error correction
Poupart-Lavoie, Geneviève. "Développement d'une méthode de transfert des mises à jour de données à référence spatiale". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq26262.pdf.
Texto completo da fonteMartowicz, Patrick. "La protection des données de télédétection spatiale en droit privé comparé français et allemand". Toulouse 1, 1996. http://www.theses.fr/1996TOU10003.
Texto completo da fonteRemote sensing data is the very best example of new goods which statute law and jurisprudence consider only with great difficulties. The reason for lays in the non corporeal nature of those and its contents, ie the information itself. Therefore, analysis of the protection of remote sensing data requires the study of the possible appropriation through property right and copyright or neighbouring rights but also contract law and unfair competition. This approach underlines the differences between the French and the German system. For this reason, the European community has undertaken a directive draft proposal, creating a new right, sui generis which would apply on data bases notwithstanding copyright or neighbouring rights on the content of the latter. This sui generis right however is being presented as a new one; but it rather seems to be a quasi property right which had already been mentioned in some cases related to news information in the early century
Ouattara, Mamadou. "Fouille de données : vers une nouvelle approche intégrant de façon cohérente et transparente la composante spatiale". Thesis, Université Laval, 2010. http://www.theses.ulaval.ca/2010/27723/27723.pdf.
Texto completo da fonteIn recent decades, geospatial data has been more and more present within our organization. This has resulted in massive storage of such information and this, combined with the learning potential of such information, gives birth to the need to learn from these data, to extract knowledge that can be useful in supporting decision-making process. For this purpose, several approaches have been proposed. Among this, the first has been to deal with existing data mining tools in order to extract any knowledge of such data. But due to a specificity of geospatial information, this approach failed. From this arose the need to erect the process of extracting knowledge from geospatial data in its own right; this lead to Geographic Knowledge Discovery. The answer to this problem, by GKD, is reflected in the implementation of approaches that can be categorized into two: the so-called pre-processing approaches and the dynamic treatment of spatial relationships. Given the limitations of these approaches we propose a new approach that exploits the existing data mining tools. This approach can be seen as a compromise of the two previous. It main objective is to support geospatial data type during all steps of data mining process. To do this, the proposed approach will exploit the usual relationships that geo-spatial entities share each other. A framework will then describe how this approach supports the spatial component involving geo-spatial libraries and "traditional" data mining tools
Baillargeon, Sophie. "Le krigeage : revue de la théorie et application à l'interpolation spatiale de données de précipitations". Thesis, Université Laval, 2005. http://www.theses.ulaval.ca/2005/22636/22636.pdf.
Texto completo da fonteInscrite au Tableau d'honneur de la Faculté des études supérieures
Ubéda, Thierry. "Contrôle de la qualité spatiale des bases de données géographiques : cohérence topologique et corrections d'erreurs". Lyon, INSA, 1997. http://theses.insa-lyon.fr/publication/1997ISAL0116/these.pdf.
Texto completo da fonteThis work concerns spatial data quality checking in geographical data sets, and especially existing geographical vector databases. Methods developed in this work are not dedicated to a particular data model, but can be adapted to all database fulfilling the two criteria previously given. Concerning the issue of data quality enrichment, this study concerns two complementary levels, namely the conceptual and the semantic level. For each level, processes are developed :- At the conceptual level, geometric properties applicable to geographical data types depending on the dimension of the shape that represents them (0, 1 or 2) are defined. This approach is only based on the objects that compose the database and not on the data model itself. It can then be adapted to every vector geographical data set. - At the semantic level, spatial relation among objects of the database are taken into account by means of topological integrity constraints. They allow to define topological situation that should or should not happen
Bergès, Corinne. "Étude de systèmes d'acquisitions de données dans deux milieux contraignants : expérimentation spatiale et prospection sismique". Toulouse, INPT, 1999. http://www.theses.fr/1999INPT026H.
Texto completo da fonteFavetta, Franck. "Ambiguïtés dans les langages visuels d'interrogation spatiale et précision topologique des bases de données spatiales". Marne-la-Vallée, 2003. http://www.theses.fr/2003MARN0156.
Texto completo da fonteToday, a growing panel of users has access to Information Systems and spatial datas, as Geographical Information Systems. This panel includes an increasing number of non-experts users. This fact implies a big need of user-friendly interfaces. In the domain of spatial queries, visual languages rightly meet this requirement. Nevertheless, visual languages suffer from important ambiguities that make them hard to use. Concerning the spatial expressive power, certain queries need a better topological precision than a description of the set of relations between two objects. These issues are linked and the topological expressive power can also meet problems of inconsistency. In order to solve these problems, a taxonomy of ambiguities has been built and solutions have been tested with potential users. A notion a ternary topological models has also been introduced. Especially, a model called 27 Intersections model, which extends an existing model, provides a high precision between three regions and guaranties consistency of their relations. Beyond query languages, ternary models are useful for image description, particularly in the field of medical image description in which a model has been proposed. Integration of the 27 Intersections model in OpenGIS has been presented
Boneva, Iovka. "Expressivité, satisfiabilité et model checking d'une logique spatiale pour arbres non ordonnés". Lille 1, 2006. https://ori-nuxeo.univ-lille1.fr/nuxeo/site/esupversions/dffac6b2-50d6-4e6d-9e4c-f8f5731c75e2.
Texto completo da fonteMérand, Antoine. "Etude à haute résolution spatiale des Céphéides". Paris 7, 2005. http://www.theses.fr/2005PA077155.
Texto completo da fonteAzomahou, Théophile. "Dépendance spatiale et structure de données de panel : application a l'estimation de la demande domestique d'eau". Université Louis Pasteur (Strasbourg) (1971-2008), 2000. http://www.theses.fr/2000STR1EC08.
Texto completo da fonteThis thesis deals with the estimation of spatial models with applications to the residential demand for drinking water. The main results are of two-fold. From a theoretical viewpoint, I investigate the asymptotic biais of the ordinary least squares estimator for spatial autoregressive models. I show that this estimator is biased as well as inconsistent regardless of the distribution of the disturbance. For the general spatial model, I show that the generalized method of moments (GMM) estimator of Kelejian and Prucha (1998, 1999) matches the asymptotic least squares procedure. Then, I suggest an efficient estimation of the general model based on optimal nonparametric instruments. I also provide a consistent (in probability) nonparametric estimatior of the sample autocovariances function for an irregularly spaced spatial process. I then derive the consistency in norm L2 of the resulting asymptotic variance-covariance matrix estimator. Finally, the asymptotic distribution of the GMM estimator is stated. From an empirical viewpoint, I investigate spatial dependence in the residential demand for water from two panel data samples. Estimation results indicate spatial patterns in households' demand for drinking water
Pivano, Cyril. "Désagrégation spatiale des données de mobilité du recensement de la population appliquée à l'Ile-de-France". Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1185/document.
Texto completo da fonteAcevedo, César. "Extrapolation spatialisée d'une mesure locale de l'état hydrique de la vigne à partir de données auxiliaires". Montpellier SupAgro, 2009. http://www.theses.fr/2009NSAM0023.
Texto completo da fonteThis thesis focused on the spatial estimation of vines water status. Its objective was to propose and validate an approach to take into account the spatial variability in order to better estimate the plant water status at a given date. After a state of the art showing tools and methods exist for estimating the water status of plants, this thesis showed, firstly, the availability of measurements of reference to estimate the plant water status with a low spatial resolution and secondly, the existence of information with high spatial resolution but indirectly related to the variable of interest. This state of art led to propose a collaborative approach between reference measurements and auxiliary data at high resolution. It considers a function of extrapolation of the water status which allows to take into account the spatial variability characterized by the auxiliary data on a defined area (zone of validity). Such an approach has never been proposed in the literature. In response to questions and to validate the proposed approach, experiments were carried out in nine fields of vineyard INRA Pech-Rouge (Gruissan France). A database of pre-existing thesis was also used. A database developed by the thesis was also used. These data have identified the advantages and limitations of a spatial estimation of plant water status. For moderate to severe water restriction (<-0. 4 MPa), spatial variability of vines water status is determined by certain environmental factors. The main factor identified is the soil. When the soil units are characterized, spatial variability is structured according to plant vigor. The study of information such as multispectral airborne images and the soil electrical properties showed the benefit of this information to characterize the spatial variability of plant water status. The modeling stage focused on a spatial domain corresponding to the block. For a first approach, this scale of work permits to minimize inter-block sources of variability like variety, training system, date of plantation, etc. An extrapolation model of plant water status has been proposed and validated in two databases. This model is based on a collection of site specific coefficients which are constant over time. Each coefficient, models the linear relationship between plant water status measured on a reference site, and the plant water status at a given site, regardless of date. When water restriction is large, the proposed approach can explain a significant proportion of the spatial variability of plant water status (r² = 0. 70). The identification of this general model, gave the formalism to take into account the auxiliary data. Compared to a classical approach similar to the estimation of the mean field, the model with auxiliary data explains a significant part of the spatial variability of plant water status (r² = 0. 71), when water restriction is large. At the within-field level, selected auxiliary information refers mainly to plant vigor
Este trabajo de tesis se focaliza en la estimación espacial del estatus hídrico de la viña. Tiene por objetivo proponer y validar una metodología que considera la variabilidad espacial del cuartel vitícola, de manera de estimar lo mejor posible el estatus hídrico de la planta en una fecha determinada. Posterior a una revisión exhaustiva de literatura de las principales herramientas y métodos existentes para estimar el estatus hídrico de las plantas, este trabajo puso en evidencia, por un lado, la posibilidad de utilizar mediciones de referencia para estimar el estatus hídrico de planta con una baja resolución espacial y por otro, la posibilidad de utilizar información auxiliar de alta resolución espacial que está relacionada indirectamente a la variable de interés. Este trabajo propone una metodología conjunta entre las mediciones de referencia y la información auxiliar de alta resolución, la cual es original y jamás propuesta hasta ahora en la literatura. Así, se propone una función de extrapolación del estatus hídrico que considera la variabilidad espacial sobre un área determinada (zona de validación) la cual es caracterizada por datos auxiliares. Para responder a las preguntas científicas y validar la metodología propuesta, se planificó un dispositivo experimental que comprendió nueve cuarteles vitícolas de la estación experimental del INRA de Pech-Rouge (Gruissan, Francia) que permitió crear una importante base de datos. Además se utilizó una base de datos pre-existente a la tesis. Estos datos permitieron identificar las ventajas y las limitaciones de una estimación espacial del estatus hídrico de las plantas. Para restricciones hídricas moderadas a fuertes (<-0,4 MPa), la variabilidad espacial del estatus hídrico de la viña está determinada por ciertos factores ligados al medioambiente. Así, el principal factor identificado fue el suelo. Una vez que las unidades pedológicas han sido caracterizadas, la variabilidad espacial se presentó estructurada en función del vigor de las plantas. Además, el estudio de la información auxiliar tal como, imágenes aéreas y propiedades eléctricas de suelo, mostró las ventajas de esta información para caracterizar la variabilidad espacial del estatus hídrico de las plantas. Las etapas de modelización fueron concentradas a la escala del cuartel. Así, en una primera etapa, esta escala de trabajo permitió minimizar las fuentes de variabilidad entre cuarteles vitícolas ligadas al cultivar, sistema de conducción, edad de plantación, etc. Un modelo de extrapolación del estatus hídrico fue propuesto y validado sobre dos bases de datos. Este modelo fue basado sobre una colección de coeficientes sitio-específicos locales y constantes. Cada coeficiente local, permitió modelar la relación lineal existente entre el estatus hídrico medido en un sitio de referencia y el estatus hídrico medido en cualquier otro sitio al interior del cuartel, sin importar la fecha de medición. Bajo condiciones de restricción hídrica elevada, el modelo permitió explicar una parte importante de la variabilidad espacial del estatus hídrico de la planta (r2=0,70). La identificación de este modelo general, permitió proponer una metodología para introducir datos auxiliares. Comparado con un método clásico de estimación, esta última permitió explicar una parte importante de la variabilidad espacial del estatus hídrico de las plantas (r2=0,71) en condiciones de restricción hídrica elevada. A nivel de cuartel, las variables auxiliares seleccionadas están relacionadas principalmente al vigor de las plantas
Bedel, Olivier. "Geolis : un système d'information logique pour l'organisation et la recherche de données géolocalisées". Rennes 1, 2009. ftp://ftp.irisa.fr/techreports/theses/2009/bedel.pdf.
Texto completo da fonteIn this thesis, we propose a new paradigm for geographical data organization and retrieval. Our approach is based on Logical Information System (LIS) and their underlying theory: Logical Concept Analysis. First, we present a data model centered on the geographical object that allows to gather geographical objects in a flexible way. We define spatial logics that enable to describe the geometry of geographical objects and their spatial relations (topology and distance) and to organize and retrieve these objects thanks to logical inference. Then, we detail a data exploration combining dynamically interrogation, navigation and visualization. It relies on three complementary views over the explored dataset: the query, the selection and the navigation index. Last, we describe a prototype satisfying our proposal and we discuss two experiments led on real datasets
Oliveira, Fialho Fabio de. "Définition et implémentation des corrections instrumentales de la mission spatiale CoRoT". Paris 6, 2007. http://www.theses.fr/2007PA066545.
Texto completo da fonteRioux, Jean-François. "Effet de la résolution spatiale des données de couverture terrestre sur la cartographie des services écologiques urbains". Master's thesis, Université Laval, 2018. http://hdl.handle.net/20.500.11794/33306.
Texto completo da fonteUrban ecosystem services (ES) mapping is attracting a growing interest. However, the diversity of methods and data used can produce divergent results. In particular, estimating the effect of land cover (LC) data spatial resolution on mapping spatial flows of ES from greenspaces to beneficiaries remains a challenge. This study aimed to characterize this effect, in order to improve our ability to predict its magnitude for ES flows produced at different spatial scales. A high spatial resolution (1 m) LC map covering the territory of the city of Laval was acquired, and then aggregated to coarser resolutions of 3, 5, 10 and 15 m. Using these LC maps as input data, three ES were mapped: carbon storage (a global-flow ES), cooling and pollination (two local-flow ES). Results were analyzed for different land use types. Greenspaces cover was generally underestimated at a coarser spatial resolution, leading to an underestimation of calculated ES quantity. For local-flow ES, the effect of LC resolution also depended on changes in the spatial configuration of ES potential supply relative to ES demand. The magnitude of the effect varied between the different land use types, but also between different zones of analysis corresponding to the same land use type, as the effect was sensitive to the local landscape structure. These results demonstrate the importance of considering the effect of LC data spatial resolution when mapping urban ES, especially for local-flow ES. Using high spatial resolution LC data is recommended to adequately map the ES provided by the small greenspaces scattered through the urban fabric.
Toupin, Marie-Hélène. "La copule khi-carré et son utilisation en statistique spatiale et pour la modélisation de données multidimensionnelles". Doctoral thesis, Université Laval, 2017. http://hdl.handle.net/20.500.11794/27977.
Texto completo da fonteThis thesis studies the properties of the family of chi-square copulas. This is a generalization of the multidimensional normal copulas obtained by squaring the components of normal random vector. These copulas are indexed by a correlation matrix and by a shape parameter. This thesis shows how this family can be used to perform spatial interpolation and to model multidimensional data. First, the usefulness of this class of dependence structures is demonstrated with an application in spatial statistics. An important problem in that context is to predict the value of a stationary random field at a position where it has not been observed. This thesis shows how to construct such predictions using spatial models based on copulas. One focusses on the use of the family of chi-square copulas in that context. One must first assumes that the correlation matrix has a standard parametric form, such as that of Matérn, indexed by an unknown parameter associated with the force of the spatial association. This parameter is first estimated using a composite pseudo-likelihood constructed from the bivariate distributions of the observed data. Then, a spatial interpolation method using the ranks of the observations is suggested to approximate the best prediction of the random field at an unobserved position under a chi-square copula. In a second work, the fundamental properties of the chi-square copulas are studied in detail. This family allows a lot of flexibility to model multidimensional data. In the bivariate case, this family is adapted to symmetric and asymmetric dependence structures. In larger dimensions, the shape parameter controls the degree of radial asymmetry of the two-dimensional marginal distributions. Parameter estimation procedures of the correlation matrix and of the shape parameter are compared under independent and identically distributed repetitions. Finally, the formulas of the conditional expectation for the best prediction in a spatial context are established. Goodness-of-fit tests for the family of chi-square copulas are then developed. These new tests can be applied to data in any dimension. These procedures are based on two association measures based on the ranks of the observations, which avoids having to specify the marginal distributions. It is shown that the joint behavior of these two measures is asymptotically normal. The efficiency of the new goodness-of-fit procedures is demonstrated through a simulation study and is compared to a classical goodness-of-fit test based on the empirical copula.
Richer, Gaëlle. "Passage à l'échelle pour la visualisation interactive exploratoire de données : approches par abstraction et par déformation spatiale". Thesis, Bordeaux, 2019. http://www.theses.fr/2019BORD0264/document.
Texto completo da fonteInteractive visualization is helpful for exploring, understanding, and analyzing data. However, increasingly large and complex data challenges the efficiency of visualization systems, both visually and computationally. The visual challenge stems from human perceptual and cognitive limitations as well as screen space limitations while the computational challenge stems from the processing and memory limitations of standard computers.In this thesis, we present techniques addressing the two scalability issues for several interactive visualization applications.To address visual scalability requirements, we present a versatile spatial-distortion approach for linked emphasis on multiple views and an abstract and multi-scale representation based on parallel coordinates. Spatial distortion aims at alleviating the weakened emphasis effect of highlighting when applied to small-sized visual elements. Multiscale abstraction simplifies the representation while providing detail on demand by pre-aggregating data at several levels of detail.To address computational scalability requirements and scale data processing to billions of items in interactive times, we use pre-computation and real-time computation on a remote distributed infrastructure. We present a system for multi-/dimensional data exploration in which the interactions and abstract representation comply with a visual item budget and in return provides a guarantee on network-related interaction latencies. With the same goal, we compared several geometric reduction strategies for the reconstruction of density maps of large-scale point sets
Poupeau, Benoît. "Analyse et requêtes de données géographiques 3 D : contributions de la cristallographie géométrique". Phd thesis, Université Paris-Est, 2008. http://tel.archives-ouvertes.fr/tel-00481924.
Texto completo da fonteRoche, Philip. "Structuration de la végétation et organisation du paysage en Provence calcaire : approche spatiale et hiérarchique". Aix-Marseille 1, 1994. http://www.theses.fr/1994AIX11008.
Texto completo da fonteVannier, Clémence. "Observation et modélisation spatiale de pratiques agricoles territorialisées à partir de données de télédétection : application au paysage bocager". Phd thesis, Université Rennes 2, 2011. http://tel.archives-ouvertes.fr/tel-00651991.
Texto completo da fonteBanerji, Ranajoy. "Optimisation d’une mission spatiale CMB de 4eme génération". Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCC199/document.
Texto completo da fonteThe Cosmic Microwave Background radiation is a rich and clean source of Cosmological information. Study of the CMB over the past few decades has led to the establishment of a “Standard Model” for Cosmology and constrained many of its principal parameters. It hasalso transformed the field into a highly data-driven domain.Currently, Inflation is the leading paradigm describing the earliest moments of our Universe. It predicts the generation of primordial matter density fluctuations and gravitational waves. The CMB polarisation carries the signature of these gravitational waves in the form of primordial “B-modes”. A future generation of CMB polarisation space mission is well suited to observe this signature of Inflation.This thesis focuses on optimising a future CMB space mission that will observe the B-modesignal for reaching a sensitivity of r = 0.001. Specifically, I study the optimisation of the scanning strategy and the impact of systematics on the quality of polarisation measurement
Bassene, Aladji. "Contribution à la modélisation spatiale des événements extrêmes". Thesis, Lille 3, 2016. http://www.theses.fr/2016LIL30039/document.
Texto completo da fonteIn this thesis, we investigate nonparametric modeling of spatial extremes. Our resultsare based on the main result of the theory of extreme values, thereby encompass Paretolaws. This framework allows today to extend the study of extreme events in the spatialcase provided if the asymptotic properties of the proposed estimators satisfy the standardconditions of the Extreme Value Theory (EVT) in addition to the local conditions on thedata structure themselves. In the literature, there exists a vast panorama of extreme events models, which are adapted to the structures of the data of interest. However, in the case ofextreme spatial data, except max-stables models, little or almost no models are interestedin non-parametric estimation of the tail index and/or extreme quantiles. Therefore, weextend existing works on estimating the tail index and quantile under independent ortime-dependent data. The specificity of the methods studied resides in the fact that theasymptotic results of the proposed estimators take into account the spatial dependence structure of the relevant data, which is far from trivial. This thesis is then written in thecontext of spatial statistics of extremes. She makes three main contributions.• In the first contribution of this thesis, we propose a new approach of the estimatorof the tail index of a heavy-tailed distribution within the framework of spatial data. This approach relies on the estimator of Hill (1975). The asymptotic properties of the estimator introduced are established when the spatial process is adequately approximated by aspatial M−dependent process, spatial linear causal process or when the process satisfies a strong mixing condition.• In practice, it is often useful to link the variable of interest Y with covariate X. Inthis situation, the tail index depends on the observed value x of the covariate X and theunknown fonction (.) will be called conditional tail index. In most applications, the tailindexof an extreme value is not the main attraction, but it is used to estimate for instance extreme quantiles. The contribution of this chapter is to adapt the estimator of the tail index introduced in the first part in the conditional framework and use it to propose an estimator of conditional extreme quantiles. We examine the models called "fixed design"which corresponds to the situation where the explanatory variable is deterministic. To tackle the covariate, since it is deterministic, we use the window moving approach. Westudy the asymptotic behavior of the estimators proposed and some numerical resultsusing simulated data with the software "R".• In the third part of this thesis, we extend the work of the second part of the framemodels called "random design" for which the data are spatial observations of a pair (Y,X) of real random variables . In this last model, we propose an estimator of heavy tail-indexusing the kernel method to tackle the covariate. We use an estimator of the conditional tail index belonging to the family of the estimators introduced by Goegebeur et al. (2014b)
Lecointre, Albanne. "Variabilité interannuelle à décennale en Altantique nord et mers nordiques : étude conjointe d'observations, de simulations numériques et réanalyses". Grenoble 1, 2009. http://www.theses.fr/2009GRE10308.
Texto completo da fonteThis work aims to characterise and quantify the differences between large-scale oceanic climatic indices simulated by a 9-member set of realistic numerical ocean models (five hindcasts and four reanalyses). The focus is on the North Atlantic region. The following climatic indices : meridional overturning circulation and meridional heat transport, are diagnosed in the various models. The models are run over a common period of nine years. The focus of this study is climatic variability at interannual scales. The influence of numerical parameters, such as spatial configuration and resolution, and the influence of various sequential data assimilation schemes, are evaluated. We evaluate them through comparison with observed large-scale climatic indices. The model solutions exhibit a strong diversity concerning the averaged values and the temporal variations of the meridional volume and heat transports. The ocean reanalyses considered in this study, although constrained towards an observed ocean, do not converge towards the coherent large-scale climatic indices. These reanalyses are not coherent, neither between each other, nor compared to available observational estimations, underlying the difficulty to simulate coherent large-scale climatic indices with local data assimilation
Delenne, Carole. "Extraction et caractérisation des vignes à partir de données de télédétection à très haute résolution spatiale : application en Languedoc-Roussillon pour la constitution de bases de données géographiques". Paris, ENGREF, 2006. https://pastel.archives-ouvertes.fr/tel-00130407.
Texto completo da fonteThis work aims to meet the vineyard managers' needs for information, using very high spatial resolution aerial images. Three methods have been developed and compared for vine plot detection. They are based on oriented and periodical texture recognition using either a cooccurrence analysis (Haralick's contrast index) or a frequency analysis (Fourier transform and Gabor's filters). The Fourier transform calculation on a sliding window provides the best results with plot segmentation in polygons as well as a precise estimation of row orientation and interrow distance. These characteristics enable the extraction and detailed study of each vine row, designed to: 1) improve definition of plots contours, 2) detect missing vine plants and 3) characterize inter-rows. Most of the users' needs have been met during this PhD study thanks to the implementation of a semi-automatic tool for vine plot detection, segmentation and characterization
Mehdi, Benna. "Génération et inversion de données de propagation d'ondes radio à travers un noyau comètaire (Experience CONSERT - Mission Spatiale ROSETTA)". Phd thesis, Université Paul Sabatier - Toulouse III, 2002. http://tel.archives-ouvertes.fr/tel-00007990.
Texto completo da fonteFerland, Yaïves. "Intégrer par le dialogue les données socio-économiques dans un système d'aide à la décision à référence spatiale, SADRS". Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1997. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp04/mq25306.pdf.
Texto completo da fonteBaghi, Quentin. "Optimisation de l’analyse de données de la mission spatiale MICROSCOPE pour le test du principe d’équivalence et d’autres applications". Thesis, Paris Sciences et Lettres (ComUE), 2016. http://www.theses.fr/2016PSLEO003/document.
Texto completo da fonteThe Equivalence Principle (EP) is a cornerstone of General Relativity, and is called into question by the attempts to build more comprehensive theories in fundamental physics such as string theories. The MICROSCOPE space mission aims at testing this principle through the universality of free fall, with a target precision of 10-15, two orders of magnitude better than current on-ground experiments. The satellite carries on-board two electrostatic accelerometers, each one including two test-masses. The masses of the test accelerometer are made with different materials, whereas the masses of the reference accelerometer have the same composition. The objective is to monitor the free fall of the test-masses in the gravitational field of the earth by measuring their differential accelerations with an expected precision of 10-12 ms-2Hz-1/2 in the bandwidth of interest. An EP violation would result in a characteristic periodic difference between the two accelerations. However, various perturbations are also measured because of the high sensitivity of the instrument. Some of them are well defined, e.g. gravitational and inertial gradient disturbances, but others are unmodeled, such as random noise and acceleration peaks due to the satellite environment, which can lead to saturations in the measurement or data gaps. This experimental context requires us to develop suited tools for the data analysis, which are applicable in the general framework of linear regression analysis of time series.We first study the statistical detection and estimation of unknown harmonic disturbances in a least squares framework, in the presence of a colored noise of unknown PSD. We show that with this technique the projection of the harmonic disturbances onto the WEP violation signal can be rejected. Secondly we analyze the impact of the data unavailability on the performance of the EP test. We show that with the worst case before-flight hypothesis (almost 300 gaps of 0.5 second per orbit), the uncertainty of the ordinary least squares is increased by a factor 35 to 60. To counterbalance this effect, a linear regression method based on an autoregressive estimation of the noise is developed, which allows a proper decorrelation of the available observations, without direct computation and inversion of the covariance matrix. The variance of the constructed estimator is close to the optimal value, allowing us to perform the EP test at the expected level even in case of very frequent data interruptions. In addition, we implement a method to more accurately characterize the noise PSD when data are missing, with no prior model on the noise. The approach is based on modified expectation-maximization (EM) algorithm with a smooth assumption on the PSD, and use a statistical imputation of the missing data. We obtain a PSD estimate with an error less than 10-12 ms-2Hz-1/2. Finally, we widen the applications of the data analysis by studying the feasibility of the measurement of the earth's gravitational gradient with MICROSCOPE data. We assess the ability of this set-up to decipher the large scale geometry of the geopotential. By simulating the signals obtained from different models of the earth's deep mantle, and comparing them to the expected noise level, we show that their features can be distinguished
Puyou-Lascassies, Philippe. "Surveillance des comportements radiométriques en paysage agricole hétérogène avec des données satellitaires à haute et à basse résolution spatiale". Toulouse 3, 1994. http://www.theses.fr/1994TOU30270.
Texto completo da fonteNabucet, Jean. "Apport des données de télédétection à très haute résolution spatiale pour la cartographie de la végétation en milieu urbain". Thesis, Rennes 2, 2018. http://www.theses.fr/2018REN20062/document.
Texto completo da fonteAbstract: Detailed knowledge and monitoring of urban vegetation is an important issue, both for scientists studying landscape-ecosystems relationships, and for the managers who are in charge of the vegetation management. The main objective of this thesis is to evaluate the interest of THRS images to map urban vegetation. More specifically, it aims to evaluate the potential of THRS images on three components: spatial resolution, spectral resolution and altimetry. For this purpose, we processed several types of THRS optical data acquired on the City of Rennes and the Prairies Saint-Martin Site: multispectral and superspectral 2D images, 2.5D multispectral images and 3D data acquired with a bi-spectral LiDAR. Firstly, we assessed the interest of using 2D multispectral THRS images to identify and characterize vegetation and superspectral THRS images to discriminate plant species. Secondly, we assessed the contribution of THRS 2.5D and 3D multispectral data to map vegetation patterns in urban areas using spectral, contextual and height variables. Thirdly, we sought to evaluate the impact, of the integration of vegetation information derived from THRS remote sensing data into two environmental models, one to study the landscape-biodiversity relationship, the other to analyze the landscape- urban cool island relationship