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The potential for high spatio-temporal resolution microwave measurements has urged the adoption of the signals of opportunity (SoOp) passive radar technique for use in remote sensing. Recent trends in particular target highly complex remote sensing problems such as root-zone soil moisture and snow water equivalent. This dissertation explores the continued open-sourcing of the SoOp coherent bistatic scattering model (SCoBi) and its use in soil moisture sensing applications. Starting from ground-based applications, the feasibility of root-zone soil moisture remote sensing is assessed using available SoOp resources below L-band. A modularized, spaceborne model is then developed to simulate land-surface scattering and delay-Doppler maps over the available spectrum of SoOp resources. The simulation tools are intended to provide insights for future spaceborne modeling pursuits.

Purpose:The purpose of this thesis was to identify a useful solution to find the location of a broken boundary wire. By useful we mean that the solution should be inexpensive, user friendly and accurate. However, this thesis will only investigate the accuracy of the method where the hypothesis is that an investigated method is applicable for all underground wires. Method:This study conducted a literature research in order to investigate what methods that are used in other industries to locate faults in underground, low-voltage electrical wires. After the research, the most commonly used fault locating methods were described and the one that seemed most useful was chosen as a possible solution.For the solution to be useful the accuracy was investigated. The method used to conduct an experiment and gather data to validate the solution was Design Science Research. Result:Three methods were investigated as possible solutions:Time Domain Reflectometry (TDR), Frequency Domain Reflectometry (FDR) and Murray bridge where experiments were conducted using TDR.TDR proved to be unapplicable in locating faults in boundary wires, although it was confirmed to be a valid solution to locate faults in coaxial cables with <1% error margin.What makes TDR and other reflectometry methods unsuitable methods within the autonomous lawn mower industry is the lack of characteristic impedance in the used boundary wires. The hypothesis that an investigated method is applicable for all underground wires is thereby refuted. Limitations:Experiments were conducted in laboratory environment with a signal generator and an oscilloscope. One experiment was conducted on a boundary wire in the ground which provided no reflected signal.

La mesure de champs de température sans contact est un paramètre clé pour l'optimisation et le contrôle des procédés. Les systèmes actuels présentent des limitations, particulièrement sur des surfaces hétérogènes et/ou dans des conditions dynamiques pouvant entraîner une altération de la surface. Ces restrictions sont causées par la méconnaissance de l'émissivité de la surface qui est une fonction complexe de nombreuses grandeurs physiques (température, longueur d'onde, rugosité, direction de détection). La thèse présentée propose le développement complet d'une nouvelle méthode de mesure de champs de température vraie, dénommée THERMOREFLECTOMETRIE, applicable sur tout type de matériaux opaques, dans la gamme [300-1000]°C. Elle permet la mesure en ligne de l'émissivité par le couplage d'une étape classique de THERMOGRAPHIE avec une étape de REFLECTOMETRIE laser. La démarche adoptée consiste premièrement en l'analyse critique de la méthode et de ses facteurs d'influence, ainsi que du dimensionnement optimal des éléments par des études en simulations. Ensuite un prototype opérationnel est mis en oeuvre et ses défauts sont caractérisés, du point de vue d'un système de type CAMERA, et les corrections nécessaires sont mises en place. Enfin, les performances expérimentales sont évaluées sur des scènes thermiques complexes et hétérogènes qui mettent en évidence la bonne précision du prototype pour tous les échantillons testés / True temperature field measurement is a key parameter for the optimization and the control of industrial processes. Current systems present limitations, especially on heterogeneous surfaces and/or in dynamical conditions involving the surface's variation. These restrictions are due to the ignorance of the surface's emissivity, which is a complex function of many physical quantities (temperature, wavelength, roughness, direction of detection). This thesis presents the complete development of a new method of true temperature field measurement, called Thermoreflectometry, applicable on any kind of opaque material, in the range [300-1000]°C. It allows the on-line measurement of emissivity by mixing a step of classical THERMOGRAPHY with a step of laser REFLECTOMETRY. The approach of this work is, first, the critical analysis of the method and its influence quantities, and then the optimal dimensionment of the components by simulation studies. Thirdly, a prototype is built and its defaults are characterized, following a CAMERA-based point of view, and the possible corrections are implemented. Finally, the experimental performances are estimated on some complex heterogeneous thermal scenes which emphasize the prototype's precision for all the tested samples

O objetivo do trabalho foi avaliar o desempenho do reflectômetro no domínio do tempo (TDR) comparativamente ao tensiômetro com manômetro de mercúrio (considerado como instrumento padrão), dando-se ênfase na sensibilidade de detecção de variações na umidade do solo sob condições de molhamento e secagem. Foi instalado um experimento em um solo classificado como Nitossolo Vermelho distrófico latossólico de textura muito argilosa, localizado próximo ao Posto Meteorológico do Departamento de Ciências Exatas, ESALQ/USP, Piracicaba (SP), Brasil, 22 o 42’ 30’’ de latitude sul e 47 o 38’ 00’’ de longitude oeste. Com dados de um ensaio de determinação da condutividade hidráulica do solo pelo Método do Perfil Instantâneo, de um período de secagem e de inundações intermitentes do solo, analisou-se a concordância entre a constante dielétrica obtido pelo TDR e o potencial matricial da água no solo obtido pelo tensiômetro, além dos valores de umidade volumétrica obtidos pelas mesmas técnicas. Concluiu-se que o desempenho do TDR foi superior ao do tensiômetro sob condições de secagem do solo e na detecção de variações de umidade. / The performance of a time domain-reflectometer (TDR) was compared with a mercury tensiometer (considered to be the norm), emphasizing the detection of variations in soil water content under wetting and drying conditions (as in instantaneous profile method to determine soil hydraulic conductivity). An experiment was performed in a Nitossolo Vermelho distrófico latossólico argiloso (Brazilian classification system), close to the meteorological observatory of the ESALQ/USP, Piracicaba (SP), Brazil, latitude 22 o 42’30’’ S, longitude 47 o 38’00’’ W. Data of matric potential, dieletric constant and water content during a dry period and water application were analyzed. The TDR cable tester was better than the tensiometer to detect the soil moisture variation.

Este trabalho apresenta um estudo da técnica da Reflectometria no Domínio do Tempo - TDR, para qualificação de álcool combustível. Há grande interesse na qualificação de combustíveis pois a adulteração é uma prática comum no Brasil e tem implicações nocivas no funcionamento do motor, causa maior poluição ambiental e evasão fiscal. O presente estudo foi focado em etanol adulterado com água, utilizando uma sonda comercial e sondas desenvolvidas neste trabalho, tendo sido dividido em três etapas: a primeira etapa consistiu em confirmar a viabilidade da técnica TDR para o tema proposto utilizando o sensor comercial de umidade de solo VG400 da Vegetronix, enquanto que o segundo passo tratou da simulação de sondas dos tipos bifilar, microstrip, coaxial e helicoidal em simulador tridimensional de eletromagnetismo, visando a escolha e otimização do tipo de sonda a ser usada para a qualificação do combustível. O terceiro e último passo consistiu na fabricação das sondas simuladas escolhidas e na realização de ensaios utilizando amostras de etanol com variadas proporções de água. Este estudo mostrou que a sonda helicoidal, que é uma proposta original deste trabalho, apresentou maior sensibilidade entre os modelos escolhidos, mostrando uma variação de resposta entre as amostras de etanol e água puros 12,5% maior que a sonda bifilar, que é a segunda sonda mais sensível dentre as estudadas. / This work presents a study of the Time-Domain Reflectometry - TDR technique for ethanol fuel qualification. There is a great interest in fuel qualification since adulteration is a common practice, which brings harmful consequences to the vehicle motor functioning, besides causing higher environmental pollution and tax evasion. The present study is focused on the qualification of ethanol adulterated with water, by using a commercial probe and probes developed in this work. It was divided in three steps: the first step has confirmed the viability of the technique for the proposed theme using a commercial sensor Vegetronix VG400 for soil moisture analysis. The second step was the simulation of bifilar, microstrip, coaxial and helical probe geometries using a 3D eletromagnectics software, leading to the optimization of the probe for fuel qualification. The last step was the fabrication of the simulated probes and the test of their performance into alcohol adulterated with various proportions of water. This study showed that the helical probe, an original proposal of this work, presented higher sensibility among the chosen models. Its response variation between pure alcohol and pure water was 12.5% greater than the bifilar probe, which was the second most sensitive sensor among the studied geometries.

Em função do número reduzido de estudos sobre o movimento da água e de íons no bulbo molhado, foi realizado este trabalho com o objetivo de avaliar a distribuição de água e concentração de nutrientes no bulbo formado pelo sistema de gotejamento enterrado em comparação ao superficial. O ensaio foi conduzido na área experimental do Departamento de Engenharia Rural da Escola Superior de Agricultura "Luiz de Queiroz" - ESALQ/USP, localizada no município de Piracicaba, SP. Para a avaliação foram abertas trincheiras e instaladas sondas de TDR, para o monitoramento da distribuição da solução, dispostas a 0,5; 0,15; 0,25; 0,35 e 0,45 m - profundidade, e a 0,5; 0,15; 0,25; 0,35 m - comprimento, totalizando 17 sondas em malha por trincheira. A solução de KNO3 foi aplicada a partir de gotejadores com diferentes vazões (2 e 4 L/h), sendo aplicado o volume de 1 L em intervalos de 1 hora, totalizando 10 L de solução por repetição, Conjuntamente ao monitoramento da distribuição da solução no solo, medições da área superficial molhada e do disco saturado foram feitas com régua milimetrada, além disso, foi estabelecido um volume de controle onde foram avaliadas a uniformidade de aplicação de água e KNO3. Desta forma, foi possível verificar que: em relação aos sistemas superficiais, os sistemas enterrados apresentaram menor área superficial molhada e atingiram uma maior largura e profundidade; a umidade inicial do solo influencia a formação do bulbo molhado e o movimento do KNO3 no solo; a uniformidade de sais distribuídos no volume de controle é afetada negativamente pelo aumento do volume aplicado e as maiores concentrações de água e concentração de KNO3 foram obtidas próximas ao ponto de emissão. / In function of the reduced number of studies on the water and ions movement in the wet soil volume, this work was conducted with the goal of evaluating the distribution of water and nutrient concentration in the wetted soil volume formed by subsurface drip irrigation (SDI) in comparison to surface system. The rehearsal was concducted in the experimental area of the Rural Engineering Department - ESALQ/USP, located in Piracicaba, SP. Trenches were opened and installed probes of TDR for studying to solution distribution, to facilitate the study a mesh of probes was disposed to 0,5; 0,15; 0,25; 0,35 and 0,45 m - depth, and to 0,5; 0,15; 0,25; 0,35 m - length, with the total of 17 probes. The solution of KNO3 was applied starting from emitters with different flows (2 and 4 L/h), it was applied the volume of 1 L within intervals of 1 hour, with the total of 10 L of solution for repetition. All together to study the solution distribution in the soil, the wet superficial area measurements and of the saturated disc they were done by the ruler, besides, it was established a control volume where the uniformity application of water and KNO3 was analysed. This way, it was possible to verify that: in relation to the superface systems, the SDI presented smaller wet superficial area and they reached a larger width and depth; the initial soil water content influences the formation of the wetted soil volume and the KNO3 movement in the soil; the salt uniformity, distributed in the control volume, is affected negatively by the applied volume increased, and the largest concentrations of water and KNO3 were obtained close to the emission point.

Este trabalho apresenta um estudo da técnica da Reflectometria no Domínio do Tempo - TDR, para qualificação de álcool combustível. Há grande interesse na qualificação de combustíveis pois a adulteração é uma prática comum no Brasil e tem implicações nocivas no funcionamento do motor, causa maior poluição ambiental e evasão fiscal. O presente estudo foi focado em etanol adulterado com água, utilizando uma sonda comercial e sondas desenvolvidas neste trabalho, tendo sido dividido em três etapas: a primeira etapa consistiu em confirmar a viabilidade da técnica TDR para o tema proposto utilizando o sensor comercial de umidade de solo VG400 da Vegetronix, enquanto que o segundo passo tratou da simulação de sondas dos tipos bifilar, microstrip, coaxial e helicoidal em simulador tridimensional de eletromagnetismo, visando a escolha e otimização do tipo de sonda a ser usada para a qualificação do combustível. O terceiro e último passo consistiu na fabricação das sondas simuladas escolhidas e na realização de ensaios utilizando amostras de etanol com variadas proporções de água. Este estudo mostrou que a sonda helicoidal, que é uma proposta original deste trabalho, apresentou maior sensibilidade entre os modelos escolhidos, mostrando uma variação de resposta entre as amostras de etanol e água puros 12,5% maior que a sonda bifilar, que é a segunda sonda mais sensível dentre as estudadas. / This work presents a study of the Time-Domain Reflectometry - TDR technique for ethanol fuel qualification. There is a great interest in fuel qualification since adulteration is a common practice, which brings harmful consequences to the vehicle motor functioning, besides causing higher environmental pollution and tax evasion. The present study is focused on the qualification of ethanol adulterated with water, by using a commercial probe and probes developed in this work. It was divided in three steps: the first step has confirmed the viability of the technique for the proposed theme using a commercial sensor Vegetronix VG400 for soil moisture analysis. The second step was the simulation of bifilar, microstrip, coaxial and helical probe geometries using a 3D eletromagnectics software, leading to the optimization of the probe for fuel qualification. The last step was the fabrication of the simulated probes and the test of their performance into alcohol adulterated with various proportions of water. This study showed that the helical probe, an original proposal of this work, presented higher sensibility among the chosen models. Its response variation between pure alcohol and pure water was 12.5% greater than the bifilar probe, which was the second most sensitive sensor among the studied geometries.

Este trabalho de pesquisa apresenta uma nova abordagem para calibrar uma sonda helicoidal TDR, usada para medir o teor de umidade do solo. Foi empregada uma aproximação tomando em consideração a interpretação física dos valores de constantes dielétricas. As equações de calibração foram determinadas mediante um modelo dielétrico misto, quais relacionam a constante dielétrica da mistura multifase com a constante dielétrica e frações de volumes dessas componentes. Ensaios realizados em laboratório permitirem o desenvolvimento de duas equações de calibração para a avaliação de teor de umidade volumétrico e gravimétrico dos solos. A calibração foi executada com medições de constante dielétrica em diferentes líquidos e solos, usando uma sonda convencional TDR e a sonda helicoidal TDR. As leituras realizadas com as duas sondas foram depois comparadas. O modelo dielétrico das duas fases permitiu descrever a contribuição dos materiais dielétricos do corpo da sonda helicoidal e os materiais investigados. Mostrou-se que o conhecimento das características físicas e geométricas da sonda TDR usada nos ensaios é de crucial para garantir a qualidade das constantes dielétricas lidas, e conseqüentemente a determinação do teor de umidade in situ. / The objective of this work was to calibrate a coiled TDR probe used to measure the water content of soil. It was used an approach that takes into account a physical interpretation of the values of the dielectric constants. The calibration equations were determined by means of a mixed dielectric model, which relates the dielectric constant of a multi-phase mixture with the dielectric constants and volume fractions of its components. Tests carried out in the laboratory allowed development of two calibration equations for the assessment of the volumetric and gravimetric soil water content. Calibration was performed with measurements of dielectric constants in different liquids and soils, using a conventional TDR probe and a coiled TDR. The readings performed with the two probes were then compared. The dielectric model of two phases permitted describing the contribution of the dielectric material of the body of the probe coil and the materials investigated. It has been shown that knowledge of the physical and geometrical characteristics of the TDR probe used in the tests is crucial for the quality of the dielectric constant readings, and consequently the determination of water content in situ.

"Thermal infrared (IR) imaging systems are widely used in medical, industrial, and defense applications. IR imaging systems utilize a lens to focus IR radiation onto a focal plane array (FPA) of IR detectors, which transduce the IR radiation from the scene into signals that can be further processed. In conventional IR imaging systems, electronic readout integrated circuitry (ROIC) is used to read out the information from the FPA, and computer signal processing allows for an IR image to be displayed on an electronic screen. However, the ROIC decreases the thermal isolation and sensitivity of the IR detectors in the FPA, and the computer processing and electronic display increase the cost, weight, and complexity of the IR imaging system. This thesis focuses on the development of an IR direct viewing system that does not require any ROIC, computer signal processing, or electronic display. This is accomplished through the use of microelectromechanical systems (MEMS) uncooled IR imaging detectors, which consist of arrays of bimaterial thermomechanical cantilever structures that tilt as a function of IR radiation from a scene. Other members of the WPI-ME/CHSLT group have previously shown that an interferometric optical readout mechanism based on digital holography and computer processing can eliminate the need for ROIC and be used to measure the nanometer scale tilt of the structures in a MEMS-based IR imaging system that was found to have a responsivity of 1.5 nm/K. However, these previously demonstrated results required significant computer processing and an electronic display. The hypothesis of the current work is that an optomechanical readout mechanism can be used to realize an IR direct viewer without the use of ROIC, computer signal processing, or an electronic display. Three optical readout mechanisms were identified for transducing the nanometer scale deformations of the MEMS structures in the FPA into a directly observable visible light image. Two of these, one using live holography and the other using Nomarski differential interference contrast (DIC), were based on interferometry, while the third, using reflectometry, was based on geometrical optics. The identified optical readout mechanisms were analytically evaluated based on the performance and perception of the human vision system (HVS), and preliminary experimental results were obtained using optical setups constructed for all three readout mechanisms. Based on the analytical and experimental investigations, reflectometry was selected as the most suitable readout mechanism for a direct viewer. A visible light camera was used with custom software to determine a temperature sensitivity of 137 mK for the reflectometry readout, and thermal images of scenes at human body temperature were demonstrated using limited computer processing. A false color, direct view, live IR imaging system was then demonstrated based on a two color reflectometry readout and the output was characterized with respect to the color differentiation sensitivity of the HVS. The system temperature sensitivity, based on the theoretical color differentiation sensitivity of a human observer, was found to be on the order of 10 K across a measuring range of roughly 400 °C, and objects with a temperature as low as approximately 150 °C were distinguishable. The advantages and limitations of the developed IR imaging system are identified and recommendations for further developments and future work are provided."