Este trabalho estima a velocidade de fluxo da geleira Grey, localizada no Campo de Gelo Patagônico Sul, nos meses de outubro de 2011 e janeiro a abril de 2012. Os valores de velocidade foram obtidos por um algoritmo, baseado no cálculo de correlação cruzada, entre pares de imagens SAR COSMO-SkyMed e, posteriormente interpolados, para a geração de uma superfície contínua, que ilustre os valores de direção e intensidade de fluxo para toda a geleira. Os resultados foram comparados com dados meteorológicos, disponibilizados pelo Serviço Meteorológico Argentino, para interpretar o padrão sazonal na velocidade de deslocamento. Os meses de Outubro e abril registraram valores médios de velocidade de fluxo de 1,2 ± 0,6 md-1 e 1,1 ± 0,7 md-1, respectivamente. Durante o período de verão, os meses de janeiro, fevereiro e março apresentaram valores de velocidade de fluxo de 1,5 ± 0,6 md-1; 1,3 ± 0,7 md-1 e 1,4 ± 0,5 md-1 variando, diretamente, com a temperatura média mensal. Os valores mensais de fluxo da geleira Grey apresentaram uma correlação linear de 0,96 com a temperatura do ar, medida por uma estação meteorológica automática, localizada a cerca de 80 km da geleira. Os resultados indicam que os valores mensais do fluxo da geleira Grey possuem uma relação positiva com a variação sazonal da temperatura. / This study aims to estimate the flow velocities of Grey Glacier, located in Southern Patagonian Ice Field, between October 2011 and May 2012. The velocity vectors of Grey Glacier were obtained by means of an algorithm based on cross-correlation between pairs of COSMO-SkyMed images and subsequently interpolated, for generate a continuous surface that illustrates the values of intensity and direction of glacier flow. The results were compared with meteorological data, provided by the Meteorological Service of Argentina, to interpret the seasonal pattern in velocity. October-April registered values of flow velocity of 1,2 ± 0,6 md-1 and 1,1 ± 0,7 md-1; respectively. During the summer, the months of January, February and March had values of flow velocity of 1,5 ± 0,6 md-1; 1,3 ± 0,7 md-1 and 1,4 ± 0,5 md-1 varying directly with the monthly average temperature. The monthly values flow of Glacier Grey presented a linear correlation of 0.96 with the air temperature measured by an automatic weather station, located about 80 km from the glacier. The results indicate that the monthly values of the Grey glacier flow are positively related to seasonal variation in temperature.

Este trabalho estima a velocidade de fluxo da geleira Grey, localizada no Campo de Gelo Patagônico Sul, nos meses de outubro de 2011 e janeiro a abril de 2012. Os valores de velocidade foram obtidos por um algoritmo, baseado no cálculo de correlação cruzada, entre pares de imagens SAR COSMO-SkyMed e, posteriormente interpolados, para a geração de uma superfície contínua, que ilustre os valores de direção e intensidade de fluxo para toda a geleira. Os resultados foram comparados com dados meteorológicos, disponibilizados pelo Serviço Meteorológico Argentino, para interpretar o padrão sazonal na velocidade de deslocamento. Os meses de Outubro e abril registraram valores médios de velocidade de fluxo de 1,2 ± 0,6 md-1 e 1,1 ± 0,7 md-1, respectivamente. Durante o período de verão, os meses de janeiro, fevereiro e março apresentaram valores de velocidade de fluxo de 1,5 ± 0,6 md-1; 1,3 ± 0,7 md-1 e 1,4 ± 0,5 md-1 variando, diretamente, com a temperatura média mensal. Os valores mensais de fluxo da geleira Grey apresentaram uma correlação linear de 0,96 com a temperatura do ar, medida por uma estação meteorológica automática, localizada a cerca de 80 km da geleira. Os resultados indicam que os valores mensais do fluxo da geleira Grey possuem uma relação positiva com a variação sazonal da temperatura. / This study aims to estimate the flow velocities of Grey Glacier, located in Southern Patagonian Ice Field, between October 2011 and May 2012. The velocity vectors of Grey Glacier were obtained by means of an algorithm based on cross-correlation between pairs of COSMO-SkyMed images and subsequently interpolated, for generate a continuous surface that illustrates the values of intensity and direction of glacier flow. The results were compared with meteorological data, provided by the Meteorological Service of Argentina, to interpret the seasonal pattern in velocity. October-April registered values of flow velocity of 1,2 ± 0,6 md-1 and 1,1 ± 0,7 md-1; respectively. During the summer, the months of January, February and March had values of flow velocity of 1,5 ± 0,6 md-1; 1,3 ± 0,7 md-1 and 1,4 ± 0,5 md-1 varying directly with the monthly average temperature. The monthly values flow of Glacier Grey presented a linear correlation of 0.96 with the air temperature measured by an automatic weather station, located about 80 km from the glacier. The results indicate that the monthly values of the Grey glacier flow are positively related to seasonal variation in temperature.

Alguns nitrocompostos apresentam atividade antichagásica resultante do processo de redução do grupo nitro com conseqüente formação de radical nitro ânion e de intermediários tóxicos ao parasita. A variação estrutural dos derivados 5-nitroheterocíclicos pode interferir no processo de redução destes compostos e, também, na atividade biológica. Neste aspecto, o estudo da redução dos nitrocompostos por meio de técnicas voltamétricas, como a voltametria cíclica e a voltametria de onda quadrada é uma forma de avaliar ou até simular o mecanismo de ação destes derivados. Assim, a avaliação de processos eletródicos e a determinação dos potenciais de redução dos nitrocompostos fornecem subsídios para a compreensão do mecanismo da atividade antiparasitária. Neste trabalho, desenvolveram-se procedimentos eletroquímicos utilizados para a determinação do potencial de redução e do potencial de meia onda de vinte e três nitrocompostos (5-nitro-2-tiofilideno 4-R-benzidrazidas e 5-nitro-2-furfurilideno 4-R-benzidrazidas), visando o emprego destes em estudos de QSPR e SAR. As determinações foram realizadas empregando-se Voltametria Cíclica e Voltametria de Onda Quadrada em célula eletroquímica de 10 mL nos meios prótico (solução tampão PIPES com eletrólito de suporte NaNO3 0,1 mol L-1), misto de DMSO/solução tampão PIPES (50% v/v) e em meio aprótico de DMSO (com eletrólito de suporte Bu4NH4BF4). O eletrodos de referência e auxiliar utilizados foram Ag/AgCl saturado e platina. Os eletrodos de trabalho utilizados foram o carbono vítreo (meio aprótico e misto), pasta de carbono (meio misto e prótico) e pasta de carbono modificada com nitrocompostos (meio prótico). Foram realizados estudos teóricos, de modelagem molecular, e experimental, espectrofotometria UV/visível, com o objetivo de determinar a conformação de menor energia mínima global e confirmar a ocorrência de disposição estrutural co-planar. No estudo teórico, utilizou-se as metodologias de otimização de geometria, e análise conformacional dos nitrocompostos calculadas por meio de AM1 e HF3-21G* e HF6- 31G* para obtenção dos confôrmeros de menor energia mínima. Estes confôrmeros foram submetidos a cálculo de carga de ponto único (AM1), onde determinou-se os valores de energia de diversas propriedades de caráter eletrônico (energias de formação em vácuo e meio solvatado, de HOMO, de LUMO, momento de dipolo, dureza, potencial químico, afinidade eletrônica, potencial de ionização, cargas de potencial eletrostático), geométrica (volume molecular) e mapas 3D de densidade de potencial eletrostático, de HOMO e de LUMO. Todos os cálculos foram realizados empregando-se os pacotes computacionais Spartan O2 for Linux, Spartan O4 for Windows e ClogP 4.0 (para determinar os valores de hidrofobicidade). Os valores do potencial de pico catódico (Epc 1) e de meia onda bem como as propriedades físico-químicas, obtidos a partir de cálculos de química quântica, de σp e σR, ClogP e π) foram utilizados em análise de QSPR aplicando-se a Análise de Hansch e regressão multivariada, PLS. Avaliou-se ainda, a atividade antichagásica de dez nitrocompostos (oito derivados tiofilidênicos e dois derivados fufurilidênicos) visando investigar a possibilidade de influência do processo de redução dos nitrocompostos sobre a atividade biológica. Realizaram-se ensaios que permitiram avaliar o efeito antiproliferativo dos nitrocompostos sobre o parasita, em 24 horas, por meio de contagem do número de unidades viáveis em câmara de Neubauer. Os métodos voltamétricos utilizados mostraram-se adequados para a avaliação da redução eletroquímica dos nitrocompostos, e foram apropriados para a obtenção dos potenciais de redução de pico catódico e dos potenciais de meia onda de todos os derivados em meio aprótico e misto. Em meio aquoso, obtiveram-se os valores dos potenciais de redução de pico catódico apenas para os derivados tiofilidênicos. A partir dos resultados obtidos na análise conformacional, observou-se a quebra de efeito co-planar estrutural na região do anel benzênico substituído e porção hidrazídica molecular. Adicionalmente, nos mapas de densidade de potencial eletrostático, registrou-se a ocorrência de efeito mesomérico conjugado reduzido entre as porções moleculares citadas acima. De posse destes dados, em conjunto com as visualizações de sinais característicos para grupos cromóforos distintos em espectros UV/visível, sugere-se a ausência de efeito conjugado molecular e, como conseqüência, de influência dos grupos substituintes em posição para do anel benzênico sobre o grupo nitro ligado ao anel heterocíclico. Nos resultados obtidos a partir das análises de QSPR, observou-se que não ocorre correlação entre as propriedades físico-químicas, determinadas para os nitrocompostos, e os descritores eletroquímicos, obtidos em diferentes meios de reação. Diante deste fato, sugere-se que a quebra do efeito co-planar interfere diretamente na intensidade da influência das propriedades físico-químicas de grupos substituintes sobre o potencial de redução dos nitrocompostos. Observou-se, também, que a maioria dos compostos apresentou atividade antichagásica superior ao fármaco de referência, o benznidazol. Verificou-se que os compostos não substituído e cloro derivado da série dos 5-nitro-2-furfurilidênicos são mais ativos que os correspondentes análogos das 5-nitro-2-tiofilideno benzidrazidas. Em análise preliminar, observou-se que o potencial de redução e o potencial de meia onda não exercem influência sobre a atividade antichagásica dos nitrocompostos. / Some nitrocompounds have show activity against to Trypanosoma cruzi. Those biological activity are resulting from nitro group reduction with subsequent formation of radical nitro anion and other reaction\'s intermediates, which are toxic to the parasite. The structural difference among the 5-nitro-heterocyclic derivatives might exert influence on these compounds reduction and also on the antichagasic activity. In this way, the study of reduction process by voltammetric techniques, such as cyclic voltammetry and square wave voltammetry, is a mode of evaluate the biological action mechanism. Therefore, the evaluation of the electrodic process and the determination of nitrocompounds reduction potential provide information for elucidating the antitrypanosomal activity mechanism. In the present work, the procedures employed to determinate the cathodic reduction and reduction potentials were carried out on twenty three nitrocompounds (5-nitro-2-tiofilidenic benzhidrazides and 5-nitro-2-furfurilidenic benzhidrazides) with the aim using those data in QSPR and SAR analysis. Cyclic voltammetry and square wave voltammetry techniques were used to determined the reduction potential in electrochemical cell of 10 mL in the protic media (PIPES buffer and electrolyte of support NaNO3 0.1 mol L-1), mixed media of DMSO and PIPES buffer 50:50 v/v (electrolyte of support NaNO3 0.1 mol L-1), and aprotic media of DMSO (electrolyte of support Bu4NH4BF4 0.1 mol L-1). The reference and counter electrodes used were Ag/AgCl (with KCl saturated) and platinum, respectively. In these studies, the work electrodes were glassy carbon (aprotic and mixed media), carbon paste (mixed and protic media) and carbon paste modified with nitrocompounds (protic media). Molecular modeling studies and UV/visible spectrophotometry were investigated with the aim for determining the lowest conformational energy and the occurrence of co-planarity molecular structure. In this work were performed the geometry optimization (using the quantum chemistry AM1, ab initio HF3-21G* and HF6-31G* level of theory), conformational analysis(AM1 and ab initio HF6-31G*) and single point calculations (AM1). All the lowest energy conformers from conformational analysis were submitted to single point calculations. These models were used to determine the physicochemical properties (energy of formation in vacuum and solvated media, energy of HOMO, energy of LUMO, dipole moment, hardness, chemistry potential, electronic affinity, ionization potential and charges of electrostatic potential) and the molecular electrostatic potential, HOMO and LUMO maps, respectively. All calculations were performed using the computational software Spartan O2 for Linux, Spartan O4 for Windows, and the ClogP 4.0 (only for hydrophobicity). The cathodic reduction and half-wave potentials values and the set of physicochemical properties, which are obtained from quantum chemistry calculations, as well as the electronic effect (σp and σR derived of σ Hammett) and the hydrophobicity property (ClogP, and π of Hansch) were used in QSPR analysis applying Hansch analysis and PLS methodologies. Afterwards, the antichagasic activity of ten compounds (eight thiofilidenic and two furfurylidenic derivatives) was evaluated considering the influence of nitrocompounds reduction on biological activity. This assay allows to analyse the antiproliferative effect of nitrocompounds on the parasites growing, in twenty-four (24) hours, reading the number of trypanosomes in Haemocytometer. The voltammetric methodologies allowed to determinate the cathodic reduction and half-wave potential values in aprotic and mixed media to all nitrocompounds. In protic media, however, the cathodic reduction potential values were obtained only for the 5-nitro-2-tiofilidenic benzhidrazides. Those procedures seen to be appropriated for perform the electrochemistry reduction evaluation. The geometry optimization and conformational analysis allows determining a lack of structural planarity in all derivatives located at the bond between the carbonilic carbon and benzhoyl group. Additionally, the electrostatic potential maps presented a decreased on the electronic conjugate effect of the structures of nitrocompounds investigated. The conformational analysis allows us to determine the nitroheterocyclic biosostere conformations dependence on the reaction phase studied. The UV/visible spectra presented two waves, which are indicating responses related to different chromophores. These results suggest the absence of conjugate effect in nitrocompound structure, indicating that the presence of groups attached to benzene ring do not exert influence on the nitro group attached to heterocyclic ring. In the QSPR analysis was not detected any correlations between thel physicochemical properties and the cathodic reduction and reduction potentials, in all reaction media investigated. Those results might be occurred due to the lack of molecular co-planarity, which is reducing the influence of any property on the nitrocompounds reduction. Almost all nitrocompounds investigated show higher antichagasic activity than the reference drug, benznidazol. In a preliminary analysis it was verified that the cathodic reduction and half-wave potentials do not exert influence on the nitrocompounds antichagasic activity.

O estudo das formas do relevo terrestre teve um avanço expressivo com a utilização das modernas ferramentas de sensoriamento remoto. Na região Amazônica, devido à vasta cobertura de nuvens, bruma e fumaça, quase que o ano inteiro, de certa forma, ocasiona dificuldade para levantamento com sensores ópticos. As melhores imagens para a região, portanto, são as imagens provenientes de radar, pois esse sistema tem a vantagem de adquirir imagens, independente, da presença de nuvens ou fumaça. Desta forma, este trabalho teve por objetivo principal o uso das imagens do Radar de Abertura Sintética (SAR) R99B para o mapeamento geomorfológico ao longo do furo do Ariaú no município de Iranduba. A escolha desta área se justifica por apresentar características naturais e socioeconômicas bem peculiares. Na questão natural, Iranduba está encravado entre os dois maiores caudal da região: rio Negro e Solimões/Amazonas e composto de um ambiente de terra firme e várzea. Na questão socioeconômica, é nesse município que se encontra, também, o maior polo oleiro do estado do Amazonas. A metodologia empregada neste trabalho foi baseada na adaptação dos métodos propostos por Lima (1995), composta de três fases: identificação, análise e interpretação. O método proposto permitiu a interpretação das feições geomorfológicas baseadas na textura das imagens SAR/R99B com múltiplas polarizações para as terras baixas com altitude não ultrapassando 100 m. A fim de buscar entender a dinâmica fluvial da área do Ariaú foi realizado trabalho de campo e levantamento pedológico. Como resultado desta pesquisa, obteve-se mapa da drenagem, mapa geomorfológico das feições fluviais e os principais nutrientes do solo na calha do Ariaú. As imagens do SAR mostraram-se eficientes para as diferentes feições geomorfológicas para o mapeamento de média escala, no entanto, a falta de imagens nos diversos períodos hidrológicos, seca, enchente, cheia e vazante, de certa forma, compromete um melhor entendimento do ambiente. Este trabalho, portanto, coloca-se como uma perspectiva para novas interpretações geomorfológicas dos ambientes fluviais nas áreas baixas da Amazônia. / The study of the forms of terrestrial landscape had a significant progress with the use of modern remote sensing tools. In the Amazon region, due to extensive cloud cover, haze and smoke, almost the entire year, somehow, causes difficulty imaging with optical sensors. The best images for the region, are the pictures from Radar because this system has the advantage of acquiring images, independent of the presence of clouds or smoke. Thus, this work aimed to use pictures of the Synthetic Aperture Radar (SAR) R99B for geomorphological mapping along the Furo do Ariaú in the municipality of Iranduba. The choice of this area is justified due to its peculiar natural and socioeconomic characteristics. In the natural matter, Iranduba is wedged between the two major flow region: Rio Negro and Solimões /Amazonas and composed of an environment of upland and floodplain. In the socioeconomic issue, it is in this city that lays the largest polo potter in the state of Amazonas. The methodology used in this study was based on the adaptation of the methods proposed by Lima (1995), composed of three phases: identification, analysis and interpretation. The proposed method allowed the interpretation of geomorphological features based on texture of SAR/R99B images with multiple polarizations to the lowlands to an altitude not exceeding 100m. In order to try to understand the dynamics of the Ariaú river area fieldwork and soil survey were conducted. As a result of this research a map was obtained, including the drainage map, geomorphological map of the river and the main nutrients in the soil trough Ariaú. The SAR images were effective for different geomorphological mapping to medium scale, however, the lack of pictures in different hydrological periods, drought, flooding and receding somewhat, compromises a better understanding of the environment. This work, therefore, arises as a prospect for new interpretations of fluvial geomorphic low-lying areas of the Amazon.

Les images radar des surfaces planétaires fournissent une mine d'information sur l'espace imagé. La disponibilité des images SAR (Synthetic Aperture Radar) donne la possibilité de cartographier des régions inconnues, difficilement accessibles, ou peu propices à la vie de l'Homme. Cependant, les images de télédétection radar présentent plusieurs défauts, dont le speckle et une ou plusieurs formes de distorsion géométrique. L'objectif de cette étude est de développer des méthodes capables d'identifier et de caractériser des changements affectant les surfaces des dunes à partir des données satellitales acquises à différentes dates et provenant de différentes sources. Elles donnent ainsi, la possibilité de cartographier, de catégoriser et de surveiller des zones affectées par des événements naturels survenus au cours du temps. / Radar images of planetary surfaces provide a wealth of information on the imaged area. The availability of SAR (Synthetic Aperture Radar) images provides the ability to map unknown regions, difficult to access, or not conducive to the human life. However, the radar remote sensing images have several defaults, the speckle and one or more forms of geometrical distortion. The aim of this study is to develop methods that can identify and characterize changes in dune areas using satellite data acquired at different times and from different sources. So they give the possibility to map, categorize and monitor areas affected by natural events along time.

Cette thèse est dédiée à l’analyse systématique de l’espace chimique, et des relations structure-activité (SAR) en particulier. L’ouvrage présente des nouveaux protocoles d’analyse combinant des méthodes classiques et originales, dans le but d’analyser les SAR à l’échelle globale ainsi que locale. L’analyse globale des espaces chimiques repose sur la recherche des motifs structuraux privilégiés par cartographie topographique générative (GTM), ainsi que par analyse classique des « châssis » moléculaires. La cartographie a été ensuite couplée avec l’analyse de réseaux chimiques (CSN), permettant une transition de la vue globale vers l’analyse locale de SAR. L’optimisation mutiobjectif des propriétés de potentiels médicaments a été adressé par la méthode « star coordinates ». L’analyse locale des SAR inclut des nouvelles stratégies pour prédire les discontinuités dans le paysage structure-activité biologique, et une étude de l’impact de la structure sur l’ionisation des molécules. Des matrices SAR ont servi pour monitorer le progrès dans l’optimisation de nouveaux principes actifs. / This thesis presents studies devoted to aid in systematic analysis of chemical spaces, focusing on mining and visualization of structure-activity relationships (SARs). It reports some new analysis protocols, combining both existing and on-purpose developed novel methodology to address both large-scale and local SAR analysis. Large-scale analysis featured both generative topographic mapping (GTM)-based extraction of privileged structural motifs and scaffold analysis. GTM was combined with chemical space network (CSN) to develop a visualization tool providing global-local views of SAR in large data sets. We also introduce star coordinates (STC) to visualize multi-property space and prioritize drug-like subspaces. Local SAR monitoring includes new strategies to predict activity cliffs using support vector machine models and a study of structural modifications on ionization state of compounds. The SAR matrix methodology was applied to objectively evaluate SAR progression during lead optimization.

La thèse porte sur la quantification d'incertitude de paramètres (Uncertainty Quantification ou UQ) dans le calcul du débit d'absorption spécifique (Specific Absorption Rate ou SAR) de téléphones mobiles. L'impact de l'incertitude, ainsi le manque de connaissances détaillées sur les propriétés électriques des matériaux, les caractéristiques géométriques du système, etc., dans le calcul SAR est quantifiée par trois méthodes de calcul efficaces dites non-intrusives : Transformation non parfumée (Unscented Transformation ou UT), collocation stochastique (Stochastic Collocation ou SC) et polynômes de chaos non-intrusifs (Non-Intrusive Polynomial Chaos ou NIPC).Ces méthodes sont en effet appelées méthodes non intrusives puisque le processus de simulation est tout simplement considéré comme une boîte noire sans que ne soit modifié le code du solveur de simulation. Leurs performances pour les cas de une et deux variables aléatoires sont analysées dans le présent travail. En contraste avec le procédé d'analyse d'incertitude traditionnel (la méthode de Monte Carlo ou MCM), le temps de calcul devient acceptable. Afin de simplifier la procédure UQ pour le cas de plusieurs entrées incertaines, il est démontré que des incertitudes peuvent être combinées de manière à évaluer l'incertitude sur les paramètres de la sortie.Combiner des incertitudes est une approche généralement utilisée dans le domaine des mesures, et ici, il est utilisé dans le calcul du SAR pour la situation complexe. Une des étapes nécessaires dans le cadre de l'analyse d'incertitude est l'analyse de sensibilité (Sensitivity Analysis ou SA), qui vise à quantifier l'importance relative de chaque paramètre d'entrée incertain par rapport à l'incertitude de la sortie. La méthode reposant sur le calcul des indices de sensibilité de Sobol est employée, ces indices étant évalués par un développement en polynômes de chaos, au lieu d'utiliser la méthode de Monte-Carlo dans le calcul SAR. Les résultats des investigations sont présentés et discutés.Afin de faciliter la lecture, des notions élémentaires de débit d'absorption spécifique, de modélisation, d'incertitude dans la modélisation, de théorie des probabilités, et de calcul SAR par l'un des solveurs de simulation sont proposés dans l'Introduction (chapitre 1). Puis l'usage des méthodes non-intrusives UQ telles que UT, SC et NIPC, et l'application de la méthode des indices de Sobol pour l'analyse de sensibilité dans le calcul SAR est présentée dans les chapitres 2 et 3. Dans le chapitre 4, une autre approche d'utilisation des polynômes de chaos est fournie, et elle est utilisée dans le domaine temporel par l'intermédiaire d'un code de différences finies (Finite Difference-Time Domain ou FD-TD). Puisque le code FD-TD dans le solveur de simulation peut en effet être modifié, c'est le développement en polynômes de chaos intrusifs, étudié en détail par un certain nombre de scientifiques déjà, qui est considéré. Dans le chapitre 5, les conclusions et un aperçu des travaux futurs sont fournis. / This thesis focuses on parameter uncertainty quantification (UQ) in specific absorptionrate (SAR) calculation using a computer-aided design (CAD) mobile phone model.The impact of uncertainty, e.g., lack of detailed knowledge about material electricalproperties, system geometrical features, etc., in SAR calculation is quantified by threecomputationally efficient non-intrusive UQ methods: unscented transformation (UT),stochastic collocation (SC) and non-intrusive polynomial chaos (NIPC). They are callednon-intrusive methods because the simulation process is simply considered as a blackboxwithout changing the code of the simulation solver. Their performances for thecases of one and two random variables are analysed. In contrast to the traditionaluncertainty analysis method: Monte Carlo method, the time of the calculation becomesacceptable. To simplify the UQ procedure for the case of multiple uncertain inputs, it isdemonstrated that uncertainties can be combined to evaluate the parameter uncertaintyof the output. Combining uncertainties is an approach generally used in the field ofmeasurement, in this thesis, it is used in SAR calculations in the complex situation. Oneof the necessary steps in the framework of uncertainty analysis is sensitivity analysis (SA)which aims at quantifying the relative importance of each uncertain input parameterwith respect to the uncertainty of the output. Polynomial chaos (PC) based Sobol’indices method whose SA indices are evaluated by PC expansion instead of Monte Carlomethod is used in SAR calculation. The results of the investigations are presented anddiscussed.In order to make the reading easier, elementary notions of SAR, modelling, uncertaintyin modelling, and probability theory are given in introduction (chapter 1). Thenthe main content of this thesis are presented in chapter 2 and chapter 3. In chapter 4,another approach to use PC expansion is given, and it is used in the finite-differencetime-domain (FDTD) code. Since the FDTD code in the simulation solver should bechanged, it is so-called intrusive PC expansion. Intrusive method already investigatedin details in other people’s thesis. In chapter 5, conclusions and future work are given.

Einen großräumigen Überblick über ein Gebiet von Interesse können Satellitenbilddaten ermöglichen. Dabei werden räumliche Beziehungen erkennbar und lassen sich untersuchen. Die Bestimmung der räumlichen Verteilung und des zeitlichen Ausmaßes eines großräumigen Ereignisses, wie einer Überflutung, ist oftmals nur mit Unterstützung von fernerkundlichen Daten möglich. Es besteht der Bedarf an kontinuierlichen Informationen über den Zustand eines Systems über einen längeren Zeitraum, wenn Zusammenhänge zwischen den natürlichen Schwankungen und unterschiedlichen anthropogenen sowie natürlichen Einflüssen untersucht werden sollen. Das Nigerbinnendelta in der Republik Mali nimmt in der semi-ariden Region eine besondere Stellung ein, da es sich um einen Gunststandort handelt, der wesentlich zur wirtschaftlichen Entwicklung der Region beiträgt. Die im Rahmen dieser Arbeit zu erstellende Datenbasis beruht auf SAR-Daten, deren größter Vorteil in der Wetter- und Tageszeitunabhängigkeit liegt. Eine Herausforderung bei der Nutzung von Radaraufnahmen sind die spezielle Bildgeometrie, der auftretende Speckle-Effekt sowie das komplexe Rückstreuverhalten der Strahlung. Die Datenbasis bilden ERS- und Envisat-Aufnahmen, deren Auswertung zunächst die Datenaufbereitung bzw. die Vorverarbeitung, u. a. in Form einer radiometrischen Kalibrierung und einer Speckle-Filterung, vorangestellt ist. Die Anwendung von pixelbasierten Auswertemethoden ist aufgrund der radiometrischen Eigenschaften der Daten weniger geeignet, weshalb die in der Fernerkundung neuere objektorientierte und wissensbasierte Klassifikation zur Anwendung kam. Das Fehlen von zeitnah erhobenen Geländebeobachtungen sowie das komplexe Rückstreuverhalten der Mikrowellen erfordern eine ausführliche Auseinandersetzung mit dem Untersuchungsgebiet sowie mit dem Verhalten der C-Band SAR-Daten in Feuchtgebieten. Innerhalb der SAR-Daten treten vermehrt Überschneidungen in der Rückstreuung unterschiedlicher Landbedeckungen auf. Deren Trennung erfordert Vorkenntnisse über die Ausbreitung der Landbedeckungen zu unterschiedlichen hydrologischen Stadien. Die zum Aufbau der wissensbasierten Auswertung erfolgte Auseinandersetzung mit dem Untersuchungsgebiet beinhaltete neben der geographischen Aufbereitung die Erstellung einer Vergleichsbasis, basierend auf multispektralen Aufnahmen. Auf Grundlage je einer Aufnahme während sowie nach der Überschwemmung wurden für die objektorientierte Klassifikation zwei Regelwerke, in die neben der auszuwertenden SAR-Aufnahme zusätzliche Informationen wie z. B. der Texturparameter Entropie eingingen, erstellt. Das Ergebnis ist eine Datenbasis der Überschwemmungsflächen zu verschiedenen Aufnahmezeitpunkten. Die Evaluierung von zwei Klassifikationsergebnissen ergab eine sehr gute Trennung der überschwemmten und nicht überschwemmten Bereiche. Die aufbereiteten SAR-Daten geben einen Überblick über die Ressource Wasser für bereits vergangene Zeitschnitte. Zusammen mit aktuellen Informationen können diese einen Beitrag für ein nachhaltiges Management dieser Lebensgrundlage im Nigerbinnendelta leisten.

The Phase Gradient Autofocus (PGA) algorithm is widely used in spotlight mode SAR for motion compensation. The Maximum Likelihood PGA (ML PGA) algorithm has been shown to be a superior autofocus method. The PGA is restricted to high altitude aircraft. Since lower altitude SARs have significant range dependencies that cannot be ignored, the PGA could not be used. This thesis eliminates the high altitude restriction and extends the PGA for use with all spotlight SARs. The new algorithm is tested with three images. Each image has a unique quality. A desert image provides a low signal to clutter ratio with no distinct targets and the mountain image has areas with high signal-to-clutter and areas with low signal-to-clutter. Each image was corrupted with a low frequency and high frequency motion induced low altitude phase error. The new Phase Weighted Estimation (PWE) low altitude autofocus method converged to a lower standard deviation than the ML PGA, but required more iterations. Another limitation of the PGA is that it will only work for spotlight SAR. In this thesis, the spotlight PGA is extended to stripmap by using a conversion similar to spotlight mode. With the space frequency relationship an altered PGA is used to extend the PGA to stripmap mode SAR. The stripmap SAR, range dependant PGA allows for focusing of low altitude low cost stripmap SARs. The phase weighted estimation method is extended to range dependent stripmap. The stripmap mode estimator is most successful with high signal-to-noise images.

The research investigates the influence on the human body on a communication system. To understand this, the effect of hands free kit (HFK) on energy absorption in the body was investigated when operating a smart phone at 2G. Findings on the research are given in the thesis report. Also, the influence of the way in which a phone is held on a phone s received power was investigated. The result was compared to that obtained using a hand phantom acquired from SPEAG. This was to check if the hand phantom best represents the human hand when using it in experiments. The setup for the experiment was in an anechoic chamber at Loughborough University. The mobile phone transmitted in the 2G system. In further experiments carried out on the body, two antennas were attached to the body in six different orientations to receive power from a source creating a Single Input Multiple Output (SIMO) system. The antennas used were monopoles mounted on a circular ground plane. These antennas were designed and constructed with the influence of the body taken into consideration. The use of diversity techniques to improve transmission to an on-body system is investigated with the antennas on the body. For each alignment, the transmission to the on-body was compared with the transmission to the corresponding off-body (free space). Experiments for this work were carried out in three environments.