Orientador: Edson Eiji Matsura / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-09T04:32:01Z (GMT). No. of bitstreams: 1 Roque_MarcioWilliam_D.pdf: 4566160 bytes, checksum: e232b1dbf290d1893cd9821cda298632 (MD5) Previous issue date: 2007 / Resumo: Diante da importância da necessidade de água para irrigação, torna-se imprescindível a conscientização do produtor rural com relação ao seu manejo racional, pois a irrigação tem sido apontada, ao longo das últimas décadas, como a grande consumidora de água. Diversos trabalhos têm mostrado que a prática do manejo racional da irrigação associada ao sistema plantio direto leva o agricultor a produzir igual ou até mais, em relação ao plantio convencional, com um menor consumo de água, evitando-se assim, o desperdício desse recurso, além de contribuir para o desenvolvimento de uma agricultura sustentável. Entretanto, dependendo do tempo, das condições de implantação e manejo do plantio direto, em muitas lavouras verificou-se um aumento do estado de compactação, com aumento de densidade do solo e da resistência mecânica à penetração, causando perda na produção. Diante do exposto, o objetivo deste trabalho foi avaliar a dependência espacial dos atributos físico-hídricos do solo e da produção, verificando-se as inter-relações destes com a produção de grãos do feijoeiro irrigado sob sistema plantio direto e convencional, e também verificar o uso da técnica Reflectometria no Domínio do Tempo (TDR) no monitoramento da umidade do solo nos mesmos sistemas. Para isso foi semeado o feijão como cultura de inverno durante as safras de 2005 e 2006 em quatro parcelas experimentais conduzidas sob plantio direto e convencional, irrigado e não irrigado. Em cada parcela experimental de dimensões de 20 x 30m, foram definidas malhas de amostragem de 3 x 3m, totalizando 60 pontos amostrais por parcela. O solo das parcelas pertence à classe Latossolos Vermelhos Distroférricos típicos. Nos pontos amostrais foram inseridas sondas de TDR para o monitoramento da umidade do solo, e determinada a condutividade hidráulica saturada, a resistência do solo à penetração e retirada de amostras para a determinação da densidade do solo. Utilizando-se de um nível óptico foi determinada a cota em metros de cada ponto amostral nas parcelas estudadas. A análise da dependência espacial foi avaliada por meio da geoestatística, e os parâmetros dos semivariogramas utilizados para construir mapas de isolinhas utilizando-se do interpolador de krigagem pontual disponível no programa Surfer 8.0. Os principais resultados obtidos indicaram que a calibração da TDR proposta por Topp et al. (1980) como universal, não é adequada para o solo estudado. A técnica da TDR foi eficiente no monitoramento da umidade do solo ao longo do ciclo da cultura do feijoeiro e pode ser empregada no manejo da irrigação, desde que se faça a previa calibração do equipamento para o solo estudado. Os valores de resistência do solo à penetração (RP), para os dois sistemas de manejo do solo aumentaram de uma safra para outra, sendo que no plantio direto este aumento foi superior, ultrapassando os valores de RP do plantio convencional na safra de 2006. Entretanto os valores obtidos não interferiram na produtividade do feijoeiro nos dois sistemas de preparo do solo. Os valores da condutividade hidráulica saturada, para os dois sistemas de manejo do solo aumentaram de uma safra para outra, sendo que na safra de 2006, os valores de condutividade hidráulica saturada para o sistema plantio direto foram superiores ao convencional. Com relação à densidade do solo, na safra de 2005, o plantio convencional obteve menor valor médio, e, na safra 2006, os valores médios da densidade do solo foram os mesmos para os dois sistemas de manejo. Todos os atributos físico-hídricos e a produtividade de grãos apresentaram dependência espacial nos dois sistemas de manejo do solo para as duas safras agrícolas. Com relação às inter-relações entre os atributos estudados e a produção, todas as regressões lineares simples não mostraram correlação com a produção. A regressão linear simples entre os mapas dos atributos estudados e a produção, mostrou-se significativas, com baixos valores de coeficiente de determinação. O melhor resultado obtido foi com a relação densidade do solo e a produção no sistema plantio convencional na safra 2005, com coeficiente de determinação de 43,39 %, ou seja, dentro das variáveis estudadas foi a que melhor explicou a variação da produção. Na busca de um modelo que explicasse a variação da produção em função dos atributos físico-hídricos do solo e da cota do relevo, utilizou-se da regressão linear múltipla pelo método stepwise obtendo-se modelos significativos estatisticamente que explicaram a variação da produção com coeficientes de determinação entre 27,34 % e 71,70 % / Abstract: Since last decades irrigation practices are recognized as major water consumers, requiring specific agricultural producers education and awareness on water use and supply. Recent research reports indicate significant water economy, crop yielding as well as contribution to sustainable agricultural development, if direct seedling, when compared with conventional practices, is associated to adequate irrigation management. However, depending on weather conditions as well as on the direct seedling implementation conditions, many crop plantations showed increasing soil bulk density and compaction with increasing soil mechanical resistance to penetration, causing crop production reduction. Based on what it has been exposed before, the objective of this research is to evaluate crop yielding and soil physical-hydric attributes spatial dependence as related to irrigated bean grain production associated to no-tillage and to conventional tillage systems. The Time Domain Reflectometry (TDR) efficiency in the soil moisture monitoring in the same crop systems was also evaluated. Four experimental plots with dimensions of 20m x 30m were seeded with beans in the years and 2005 and 2006 and carried under irrigated and non irrigated conventional as well as no-tillage systems. Each plot was screened with 3m x 3m sampling grids, completing a total of 60 sampling points in each plot. Plot soil was classified as Typical Distroferric Red Latossol. TDR probes were introduced into the soil on each plot to monitor moisture content, also being measured saturated hydraulic conductivity, resistance to penetration and sampling for soil bulk density determination. Elevation of each sampling point was determined by means of an optical instrument and expressed in meters. Spatial dependence analysis was evaluated through geostatistic techniques and the semivariograms parameters were employed to generate isoline maps trough the punctual kriging interpolator of the Surfer 8.0 program. Obtained results indicated TDR calibration as proposed by Topp et al. (1980), considered of universal feature, is not adequate to the soil under study. TDR technique showed to be efficient in monitoring soil moisture content throughout bean plant cycle, being applicable in the irrigation process, since a previous equipment calibration in accordance with soil type under study. Soil resistance to penetration associated to both management systems showed increased value from one harvest to the next one, being greater for no-tillage system, surpassing the RP value associated to the conventional tillage for the year of 2006. However, obtained values do not interfere in the bean plant productivity for both employed growing system. Values saturated hydraulic conductivity had increased from one harvest to the next, observing that for the year of 2006 no-tillage system showed larger values than the conventional one. Conventional tillage showed lower soil bulk density average values for the year of 2005, however these values became the same for both methods in the year of 2006 harvest. All physical-hydric attributes as well as grain productivity presented spatial dependence for both soil cultivation techniques for both harvesting periods. All of simple linear regressions showed no correlation between attributes and bean production. However, simple linear regressions showed to be significant for attribute maps and production, presenting low determination coefficient values. The best observed result was identified to be the soil density related to production for the conventional crop management, showing the determination coefficient of 43,39 %, i.e., which is considered the best explaining production variation variable. In looking for a model explaining production variation as a function of soil physical-hydric attributes and relief elevation by means of multiple linear regression by the stepwise method, statistically significant models which explains production variation between 27,34 % to 71,70 % / Doutorado / Agua e Solo / Doutor em Engenharia Agrícola

O conhecimento da movimentação da água no solo é de grande importância para a agricultura, pois a água é um dos fatores que mais influenciam no rendimento das culturas. Das várias técnicas utilizadas para o monitoramento do conteúdo de água no solo, a reflectometria no domínio do tempo (TDR) vem sendo bastante difundida entre os pesquisadores por apresentar inúmeras vantagens, dentre as quais a mensuração em tempo real e a possibilidade de leituras automatizadas. Com o objetivo de avaliar a movimentação da água num perfil de um Latossolo vermelho-amarelo, conduziu-se um experimento obtendo-se os valores de umidade do solo e condutividade elétrica através das leituras de um equipamento de TDR com sondas instaladas em uma trincheira em diversas profundidades (0,10 m a 0,60 m) e com diferentes taxas de aplicação (2, 4 e 8 L.h-1) de solução em intervalos de 1 hora, via irrigação por gotejamento. A partir dos resultados obtidos, pôde concluir-se que diferentes vazões de aplicação determinam características particulares de formação do bulbo molhado e da movimentação da solução no solo. Para as condições de solo e de acordo com o volume e a frequência utilizada durante este experimento, recomenda-se a aplicação de pequenas quantidades de solução em intervalos mais frequentes para reduzir a perda por percolação de água e solutos. / The knowledge of the water distribution in soil has great importance to the agriculture because of the crop yield the cultures income has a direct influence by the water. There are many techniques used to monity soil moisture, and the time domain reflectometry (TDR), has a satisfactory application among the researches because the advantages, allow the real time measurements can be automatized and the automatized. With the objective to appraise the water distribution and electrical conductivity in a Red-yellow Latosol profile, the experiment was conducted measuring soil moisture through the TDR equipment reading with probes fixed in a trench in various depths (0,10 m to 0,60 m) and with different applications rates of solution (2,4 and 8 L.h-1) , with one hour interval by dripping irrigation. The results allowed us to that the different sewages applications determinate the particular characteristics of the wet bulb arrangement and the water soil distribution. For the soil conditions and according to the volume and frequency used during this experiment, it is recommended to apply of small quantities of a solution at more frequent intervals to reduce the loss by percolation of water and solute.

Made available in DSpace on 2014-08-20T14:33:08Z (GMT). No. of bitstreams: 1 Dissertacao_Viviane_Santos_Silva_Terra.pdf: 2073573 bytes, checksum: 19ddda03c961d08b0c0179b761552932 (MD5) Previous issue date: 2010-02-12 / The South region of Brazil (Pelotas, state of Rio Grande do Sul) is responsible for the production of temperate fruit trees. Among them, the peach crop has been a good option for crops diversification. The knowledge of the amount of available soil water to supply water needs during the peach different stages of development is of interest to the agronomic point of view. In this sense, we highlight the importance of the use of irrigation in peach orchards in order to provide an adequate crop water supply. It is therefore important to know the response of peach to water deficit so that we can assess the influence of the practice of irrigation in crop production. Among the methodologies, the soil water balance, which consists of applying the equation of conservation of mass, has been used. Based on this, the main objective of this work was to evaluate and quantify the different components of water balance in a Red Yellow Podzolic soil, planted with peach trees, cultivar Maciel, under irrigation and without irrigation and to verify the adequacy of Domain Reflectometry Frequency (FDR) equipment for monitoring the water content over time. The evaluation and quantification of different components of water balance of soil water were measured in an experimental area which belongs to Embrapa Clima Temperado, Pelotas-RS, Brazil, planted with peach cultivar Maciel, nearby plants irrigated and not irrigated. For this, the water balance calculation was carried out weekly and divided into 32 periods, of which 4 periods (12, 20, 24 and 26) were discarded because they had precipitation above 30 mm week-1. The experimental area containing irrigated and no irrigated plants was divided into five strips. The irrigated plants belonged to the strip 1 (tubes 3 and 6), strip 2 (tube 2) and strip 3 (tube 1), each one with an area of 0.5 m². The no-irrigated area belonged to the strip 4 (tube 8) and 5 (tube 7), with an area of 1 meters each one. Strips 1, 2 and 4 were under canopy and the other outside of the canopy. Rainfall was measured by rain gauges; irrigation water supply was made based on the average daily evapotranspiration of the region; the variation of water storage in the soil was measured by readings of soil water content up to 0.50 m depth, using an equipment based on reflectometry in the frequency domain (FDR) which was calibrated from readings of tensiometers; the runoff and internal drainage or capillary rise were neglected; and the actual evapotranspiration (ETr) was taken as the unknown variable. From the results we can conclude that it is possible to use an indirect method, using tensiometers and soil water retention curves to obtain calibration curves of the reflectometry equipment in the frequency domain (FDR); the adopted irrigation management, based on the average evapotranspiration of the region, may not be sufficient to supply the water requirements of peach crop; peach trees with water supply through irrigation have higher values of actual evapotranspiration; and soil water storage ranged in all irrigated and no irrigated strips between 60 and 140 mm week-1, unaffected by the adopted treatments in the study. / A região de Pelotas é responsável pela grande produção de frutíferas de Clima Temperado, em especial a cultura do pessegueiro que tem sido uma boa opção para a diversificação de culturas. O conhecimento da quantidade de água disponível no solo para atender as necessidades hídricas do pessegueiro durante os seus diferentes estádios de desenvolvimento é de interesse do ponto de vista agronômico. Neste sentido, destaca-se o uso da irrigação na cultura do pessegueiro, visando fornecer a cultura um adequado suprimento de água. Desta forma, é importante conhecer a resposta do pessegueiro ao déficit hídrico para que se possa avaliar a influência da prática da irrigação na produção da cultura. Dentre as metodologias que tem sido utilizada, destaca-se a do balanço hídrico no solo, que consiste na aplicação da equação de conservação de massa. Baseado no acima exposto, este trabalho teve como o objetivo principal avaliar e quantificar os diferentes componentes do balanço hídrico em um solo Argissolo Vermelho Amarelo, cultivado com plantas de pessegueiro, cultivar Maciel, em condições de irrigação e sem irrigação, bem como verificar a adequação de um equipamento de Reflectometria no Domínio da Frequência (FDR) para monitorar o seu conteúdo de água ao longo do tempo. A avaliação e quantificação dos diferentes componentes do balanço hídrico de água no solo foram realizadas em uma área experimental pertencente a Embrapa Clima Temperado, Pelotas-RS, cultivada com pessegueiro, cultivar Maciel, próximo às plantas irrigadas e não irrigadas. Para tal, o cálculo do balanço hídrico foi realizado semanalmente e dividido em 32 períodos, sendo a área experimental contendo as plantas irrigadas e não irrigadas dividida em cinco faixas. As plantas irrigadas pertenciam a faixa 1 (tubos 3 e 6), faixa 2 (tubo 2) e faixa 3 (tubo 1), cada uma com área de 0,5 m². As não irrigadas pertenciam a faixa 4 (tubo 8) e faixa 5 (tubo 7), com uma área de 1,0 m² cada. As faixas 1, 2 e 4 encontravamse na subcopa da planta e as demais fora da copa. A precipitação foi medida por meio de pluviômetros; a irrigação foi feita diariamente baseada na média evapotranspirativa da região; a variação da armazenagem de água no solo foi medida por meio de leituras de umidade do solo até 0,50 m de profundidade, utilizando-se um equipamento baseado na reflectometria no domínio da frequência (FDR), o qual foi calibrado a partir de leituras de tensiometria; o escoamento superficial e a drenagem interna ou ascensão capilar foram desprezados; a evapotranspiração foi tomada como variável incógnita. A partir dos resultados podese concluir que é possível a utilização de um método indireto, usando tensiômetros e curvas de retenção para a obtenção de curvas de calibração do equipamento de reflectometria no domínio da frequência (FDR); o manejo de irrigação adotado, baseado na média de evapotranspiração da região, pode não ser suficiente para suprir a demanda hídrica da cultura do pessegueiro; plantas de pessegueiro com suprimento hídrico por meio da irrigação apresentam valores maiores de evapotranspiração real e a armazenagem variou em todas as faixas irrigadas e não irrigadas entre 60 a 140 mm semana-1, não sendo afetada pelos manejos adotados no estudo.

Abstract Light scattering diagnostics of turbid media containing both structural and dynamic inhomogeneities is currently of significant importance. One of the important directions in modern light scattering diagnostics is the development of methods for probing biological media with visible- and near-infrared radiation allowing for visualization of the biotissue structure. Optical methods for studying the biotissue structure and characterization of its optical properties are very promising and have been rapidly developing during the past decade. The present work is aimed at improving and discovering new potentials of currently existing methods of laser diagnostics of biological tissues containing both structural and dynamic inhomogeneities. In particular, the feasibilities of spatially resolved reflectometry and time-of-flight techniques for the problem of noninvasive determination of glucose level in human blood and tissues were examined both numerically and experimentally. The relative sensitivities of these methods to changes in glucose level were estimated. Time-of-flight technique was found to be more sensitive. The possibilities of Doppler optical coherence tomography for imaging of dynamic inhomogeneities with high resolution were considered. This technique was applied for the first time for the imaging of complex autowave cellular motility and cytoplasm shuttle flow in the slime mold Physarum polycephalum. The effect of multiple scattering on the accuracy of the measured flow velocity profiles for the case of single flow and for the case of the flow embedded into the static medium with strong scattering was studied. It was shown that this effect causes significant distortion to the measured flow velocity profiles and it is necessary to take this into account while making quantitative measurements of flow velocities.

Un signal GPS est modulé par une porteuse et est étalé par un code pseudo aléatoire. Sa puissance, qui est portée en dessous du niveau du bruit, ne peut pas être directement mesurée. Les estimateurs classiques de la littérature utilisent les paramètres statistiques du maximum de la corrélation, obtenus après le désétalement du signal pour mesurer la puissance du signal reçu. Ces estimateurs nécessitent une longue période d'intégration pour être précis. De plus, ils ne tiennent pas compte de l'effet de la fréquence Doppler et du nombre de satellites visibles sur la statistique du maximum de la corrélation. Ces effets perturbateurs faussent l'estimation de la valeur C/N0 et limitent les applications qui utilisent cette grandeur telle que la réflectométrie des signaux GNSS. Ce travail de thèse propose un estimateur du rapport signal à bruit propre à chaque satellite, à partir d'un signal GPS L1. Pour présenter cet estimateur, nous avons adopté une approche en deux étapes. On suppose dans la première étape que le signal GPS est numérisé sur 1 bit, et on établit une fonction reliant l'amplitude du signal reçu au maximum de corrélation. Cette fonction non linéaire est déduite de l'architecture radio du récepteur GPS et des paramètres du signal qui sont : la fréquence Doppler et le déphasage du signal reçu. En effet, le rapport signal à bruit est une mesure relative, et pour pouvoir estimer l'amplitude du signal, on suppose que le bruit est blanc, gaussien, centré et de variance unitaire. La fonction proposée étant fortement non linéaire, nous proposons dans une deuxième étape, un estimateur dynamique de l'amplitude du signal, qui utilise le filtrage d'état non linéaire et les observations du maximum de la corrélation. Deux filtres sont évalués à cet effet ; le friltrage de Kalman sans parfum et le filtrage particulaire. / A gps signal es modulated by a carrier and is spreaded by a pseudo random code. Its power, which is carried below the level of noise, can't be directly measured. Conventional estimators literature using the statistical parameters of the maximum of the correlation, obtained after despreading of the signal to measure the received signal strength. These estimators require a long period of integration to be precise. Moreover, they do not take into account the effect of the Doppler frequency and the number of visible satellites on the statistical maximum of the correlation. These disruptive effects falsify the estimated value of C/N0 and limit the applications of the reflectometry. This thesis proposes an estimator of the signal to noise ratio own to each satellite, from a GPS L1 signal. To present this estimator, we have adopted a two-step approach. it is assumed in the first stage that the GPS signal is digitized on 1 bit, and sets a function relating the amplitude of the signal received to maximum correlation knowing the parameters of the GPS signal which are : the Doppler frequency and the phase shift of the received signal. indeed, the signal to noise ratio is a relative measure, and to estimate the signal amplitude is assumed that the noise is white, Gaussian, centered and unit variance. The proposed function is highly non-linear. We propose in a second step a dynamic estimator of the signal amplitude, which uses the non-linear state filter and the observations of the maximum correlation. Two filters are assessed in this case the Unscented Kalman filter and a particle filter.

La réflectométrie GNSS (GNSS-R) est une technique d'observation de la Terre reposant sur un système radar bi-statique passif qui utilise, comme signaux d'opportunité, les signaux GNSS en bande L. Les travaux présentés dans ce manuscrit de thèse ont pour but de développer des méthodes de traitement du signal dédiées à l'altimétrie au sol par GNSS-R. L'altitude entre le récepteur GNSS-R et la surface de réflexion est déduite de la différence de chemin entre les signaux direct et réfléchi. On propose trois méthodes d'estimation dédiées à l'altimétrie par GNSS-R, pour un récepteur mono-fréquence, utilisant respectivement les observables de code, de puissance (carrier-to-noise ratio C/N₀) et de phase des signaux GNSS observés. Nous proposons un estimateur de la pseudo-distance qui utilise la mesure de délais de code sous-échantilloné aidée par la mesure de phase. On montre que l'estimateur sub-résolution proposé permet d'obtenir une précision qui est inférieure à la résolution en délai de code. Le deuxième estimateur s'appuie sur une méthode de calibration qui normalise la puissance de la somme des signaux direct et réfléchi (Interférence Pattern Technique). On montre par l'étude des bornes de Cramèr-Rao que l'estimateur proposé permet de réduire le temps de mesure et de conserver une précision centimétrique. La mesure de phase est une grandeur circulaire qui évolue linéairement avec l'élévation du satellite. Dans ce contexte, nous proposons deux estimateurs qui s'appuient sur un modèle de régression circulaire et la distribution circulaire de von Mises. Des expérimentations sur données réelles viennent conclure ce manuscrit de thèse et montrent la faisabilité des trois méthodes d'estimation proposées. La précision centimétrique est atteinte. / The Global Navigation Satellite Systems Reflectometry (GNSS-R) is an Earth observation technique. It is based on a passive bi-static radar system using the L-band signal coming directly from a GNSS satellite and this same signal reflected by the Earth surface. The aim of the presented work is to develop signal processing methods for altimetry measurements using ground based GNSS-R. The altitude is derived from the difference of path between the direct and reflected signals. We propose three estimators for GNSS-R altimetry measurement using respectively the code observations, the carrier-to-noise ratio C/N₀ observations, and the phase observations obtained by a mono-frequency receiver. Firstly, we define a pseudo-range estimator using under-sampling code delay observations aided by phase measurements. We show that the proposed estimator allows avoiding accuracy limitations due to the receiver resolution. Secondly, a calibration method has been developed for the Interference Pattern Technique, for normalizing the C/N₀ of the combination of the direct and reflected signals. The Cramèr-Rao Lower Bound of this estimation technique is studied. We show that the proposed estimator allows reducing the observation duration while keeping the centimeter accuracy. Thirdly, a last method is proposed in order to evaluate the difference of path between the direct and reflected signals using phase measurement.The phase measurement is an angular data evolving linearly with the satellite elevation. In this context, we propose two estimators based on a circular-linear regression and the von Mises distribution. Experimentation on real data conclude this manuscript and show the feasibility of these methods. The centimeter accuracy is reached.

Cette étude s’inscrit dans le cadre du diagnostic embarqué des réseaux filaires complexes. Elle vise à détecter et localiser les défauts électriques avec précision. En effet, l’intégration du diagnostic par réflectométrie dans un système embarqué fait apparaître des problèmes d’interférence qui s’aggravent dans le cas d’un réseau complexe où plusieurs réflectomètres sont placés en différents points du réseau. L’objectif est de développer de nouvelles stratégies de diagnostic embarqué des réseaux filaires complexes pour résoudre les problèmes d’interférence d’une part et l’ambiguïté de localisation du défaut d’autre part. La première contribution concerne le développement d’une nouvelle méthode de réflectométrie baptisée OMTDR (Orthogonal Multi-tone Time Domain Reflectometry). Elle utilise des signaux numériques modulés et orthogonaux pour éliminer les interférences. Pour davantage de couverture, la deuxième contribution propose d’intégrer la communication entre les réflectomètres. Elle vise à fusionner les données afin de faciliter la prise de décision. La troisième contribution adresse la problématique de la stratégie de diagnostic, c’est-à-dire, de l’optimisation des performances du diagnostic d’un réseau complexe sous contraintes opérationnelles d’utilisation. L’utilisation des Réseaux Bayésiens permet d’étudier l’impact des différents facteurs et d’obtenir une estimation de la confiance et donc, de la fiabilité du résultat du diagnostic. / This study addresses embedded diagnosis of complex wired networks. Based on the reflectometry method, it aims at detecting and locating accurately electrical faults. Increasing demand for on-line diagnosis has imposed serious challenges on interference mitigation. It aims at making diagnosis while the target system is running. The interference becomes more critical in the case of complex networks where several reflectometers are injecting their test signals simultaneously. The objective is to develop new embedded diagnosis strategies in complex wired networks that would resolve interference problems and eliminate ambiguity related to the fault location. The first contribution is the development of a new method called OMTDR (Orthogonal Multi-tone Time Domain Reflectometry). It uses orthogonal modulated digital signals for interference mitigation and thereby on-line diagnosis. For better coverage of the network, the second contribution proposes to integrate communication between reflectometers. It uses sensors data fusion to facilitate decision making. The third contribution addresses the problem of the diagnosis strategy, i.e. the optimization of diagnosis performance of a complex network under operational constraints. The use of Bayesian Networks allows us to study the impact of different factors and estimate the confidence level and thereby the reliability of the diagnosis results.

Lorsqu'une grandeur est observée par une série temporelle de mesures périodiques, telles que des mesures d'angles, les outils statistiques du domaine linéaire ne sont plus adaptés à l'estimation des paramètres statistiques de cette série. Nous proposons des filtres et un opérateur de fusion adaptés aux grandeurs aléatoires circulaires. Ils sont développés dans un cadre bayésien avec la distribution circulaire normale de von Mises. De plus, on propose un estimateur circulaire GLR (Global Likehood Ratio) de ruptures dans un signal angulaire s'appuyant sur un filtre particulaire défini dans le domaine circulaire. Le traitement des signaux GNSS repose traditionnellement sur l'estimation récursive, en boucles fermées, de trois paramètres : le délai de code, la phase et la fréquence porteuse du signal reçu. On montre dans cette thèse que l'estimation de la phase et de la fréquence en boucle fermée est à l'origine d'imprécisions et de perturbations additionnelles. On propose une nouvelle approche pour l'estimation de ces paramètres en boule ouverte. Dans ce cas, les mesures de phase sont des angles, définis entre ‒π et π. Statistiquement, elles peuvent être modélisées par la distribution circulaire de von Mises et l'on utilise donc les outils d'estimation circulaire développés dans cette thèse pour les traiter. On montre l'intérêt de l'approche proposée pour le positionnement et pour l'altimétrie par réflectométrie des signaux GNSS. La précision obtenue est de l'ordre du centimètre, pour des durées d'intégrationd'une milliseconde. On propose également une technique de résolution de l'ambiguïté de phase, utilisable dans une approche mono-récepteur et mono-fréquence. / When a value is observed by a temporal series of periodic measurements, such as angle measurements, the statistic tools of the linear domain are no longer adapted to the estimation of the statistical parameters of this series. We propose several filters and a fusion operator adapted to angular random variables estimation. They are developed in a Bayesian framework with the von Mises circular normal distribution. Moreover, we propose a Global Likelihood Ratio circular change estimator which relies on a particle filter defined in the circular domain. GNSS signal procedding traditionnaly relies on the recursive estimation of three parameters in lock loops : the code delay, the phase and the frequency of the received signal carrier. We show in this thesis that the phase and frequency estimations, when realized in a lock loop, cause imprecisions and additional perturbations. We proposea new approach for the estimation of these parameters in an open loop. in this context, the phase measurements are angles defined between ‒π et π. They can be modeled using the von Mises distribution, thus we use the developed circular estimation tools in order to process them. We show the benefit of the proposed approach for positioning and for height estimation using the GNSS-Reflectometry technique. The obtained precision is of the centimeter order, for integration times of one millisecond. We also propose a phase ambiguity resolution technique which can be used in a mono-receiver , mono-frequency approach.

Orientador: João Eduardo Guarnetti dos Santos / Banca: Marcos Roberto Bormio / Banca: Gastão Moraes da Silveira / Resumo: Este trabalho foi desenvolvido nas dependências das Fazendas Lageado e Edgárdia, pertencentes à Faculdade de Ciências Agronômicas - UNESP de Botucatu-SP, no município de Pratânia e no distrito de Vitoriana, município de Botucatu-SP, com o objetivo de avaliar 2 técnicas de obtenção do teor de água no solo. A primeira delas é conhecida como moderação de nêutrons, que consiste na emissão de nêutrons rápidos e contagem de nêutrons moderados retornados após colisão, com moléculas de hidrogênio encontradas no solo. A partir da contagem obtida, estabeleceu-se uma correlação entre essa contagem e o teor de água no solo obtido pelo método gravimétrico, tomado como padrão. Outra técnica é a do TDR (Time Domain Reflectometry) ou Reflectometria no Domínio de Tempo, onde se determina a constante dielétrica relativa do solo e, por correlação, obtém-se o teor de água correspondente. Esta técnica foi desenvolvida de 2 maneiras: na primeira, manteve-se a calibração geral conhecida como Equação de Topp, que consiste numa Equação polinomial cúbica, obtida de forma empírica. E, na segunda, desenvolveu-se uma calibração específica para cada solo analisado. Foram avaliados 7 tipos de solos às profundidades de 15 e 30cm respectivamente com 3 variações de textura: arenosa, média e argilosa. Também, determinou-se variáveis físicas, como densidade de partículas e análises químicas, dando ênfase no teor de matéria orgânica. O trabalho de campo consistiu no levantamento de dados (contagens) com a sonda de nêutrons "in situ" e na obtenção de amostras de solo, nas respectivas profundidades, para análise em laboratório pelas técnicas TDR e gravimétrica. Como referencial ou padrão, utilizou-se o método direto ou gravimétrico para a determinação do teor de água no solo...(Resumo completo, clicar acesso eletrônico abaixo) / Abstract: This work was developed at Fazenda Lageado and Edgárdia areas, belonging to the Agronomics Science School - UNESP Botucatu-SP, in Pratânia borough and in Vitoriana district, both in the Botucatu borough. The main objective was to study and evaluate two techniques to obtain the water content in the soil. The first technique evaluated is known as neutron moderation which consists in the emission of fast neutrons and in the counting of moderate neutrons which came back after a collision with hydrogen molecules found in the soil. From the coint obtained, it was settled the correlation between the count and the water content value in the soil, obtained througth the gravimetric method. Another technique is the TDR (Time Domain Reflectometry). In this, it can be determined the apparent relative constant dielectric in the soil and by the correlation, to reach the correspondent value of water content. This technique was developed in two ways: in the first one, it was kept the general calibration known as Topp's equation which consists in a cubic polynomial equation obtained in an empiric form. The second one, it was developed a specific calibration to each kind of soil analysed. It was evaluated seven kinds of soils to the depths of 15cm and 30cm, respectively. As an initial criterion to the choice of soils, we tried to obtain three texture variations: gritty sandy, mean and mudoy. It was also observed the physical variables such as: particles density and chemical analyses, giving a special emphasis on the drift of organic matter. Basically, the fieldwork consited in data surveys (count) with the neutron probe "in situ" and in the...(Complete abstract click electronic access below) / Mestre

The wavelength-division-multiplexed passive optical network (WDM-PON) offers many advantages such as large bandwidth per user, easy management, high network security and low insertion loss enabling long-reach and/or high split-ratio. However, with the rapid development and growing interest for deployment of WDM-PON, the PON systems are becoming increasingly vulnerable to various failures. Therefore, network supervision becomes extremely important to guarantee an appropriate level of network reliability performance. The aim of PON supervision is to provide automated test and diagnostic capability without compromising the available bandwidth for services. An essential function is to detect any kind of deterioration in the network that can cause suspended services and to remotely localize these faults in order to avoid the high cost arising from troubleshooting. In this thesis, we evaluate several existing WDM PON supervision methods, based on which two simple and cost-effective new solutions are proposed to localize fiber failures in WDM PON systems. In the first solution, a conventional optical time domain reflectometry (OTDR) and a switch unit are employed, while in the second method, a novel architecture based on N×N arrayed waveguide grating (AWG) is proposed. Both methods are able to localize failures in feeder fiber and drop fibers without e.g. using expensive tunable OTDRs. A patent has been filed based on the second solution. The first proposed method is validated by simulations using VPI Transmission Maker. According to the results, this supervision method is able to give accurate measurement of many different types of failures that may happen in a fiber link. Furthermore, VPI is examined in terms of its future applicability in modeling complete PON supervision methods based on OTDR.