Made available in DSpace on 2014-06-11T19:24:43Z (GMT). No. of bitstreams: 0 Previous issue date: 2013-12-19Bitstream added on 2014-06-13T18:21:03Z : No. of bitstreams: 1 000757050.pdf: 1211527 bytes, checksum: e7589291899907f7a2c5bb86c3de1113 (MD5) / Com a ocupação massiva da malha urbana e as atividades decorrentes do crescimento desordenado dessas áreas, ocorre uma alteração do clima urbano, tornando-o insalubre. Um dos fatores que contribui para a má qualidade de vida em decorrência deste fato são as ilhas de calor que consiste no acúmulo de calor na superfície e eleva a temperatura nas cidades. A vegetação urbana constituída de arborização urbana, bosques e áreas verdes, têm como função minimizar este efeito. Para conciliar esses fatores o trabalho tem como objetivo levantar os dados de temperatura de superfície através de imagens de satélite, LANDSAT 5 captada no dia 18/12/2012 dos pontos 75 e 76, órbita 221, banda 6 e levantamento in loco com termo-higrômetro, com posse dos dados, cruzar com o levantamento vegetativo realizado e proporcionar uma visão de gestão para melhorar o microclima do município em estudo. O sensoriamento remoto e o sistema de informação geográfica permitem a avaliação de diferentes temperaturas da superfície terrestre. A área reduzida do Município e a baixa resolução do sensor utilizado dificultaram a análise de temperatura da área urbana sendo necessário o uso de outros programas para auxiliar na interpretação de dados. A cobertura de vegetação na área urbana interfere diretamente na diminuição da temperatura melhorando o micro-clima urbano. As diferentes coberturas da superfície analisada também interferem na temperatura aparente. Entre as classes estudas a classe cultivo de eucalipto e mata nativa apresentaram temperatura aparente amena em torno de 22.0°C e o solo exposto a maior temperatura aparente entre 37.0°C. Os setores 4,5 e 7 apresentam uma média de temperatura de 27,0°C sendo os setores com temperatura mais amena devido a área de cobertura vegetal. A diferença de temperatura nos setores 9, 10, 12 e 13 de 32.0°C para 27.0°C é devido a existência de... / With the massive occupation of the urban and activities arising from the uncontrolled growth of these areas, a change occurs in the urban climate, making it unhealthy. One factor that contributes to poor quality of life due to this fact are the islands of heat which consists in the accumulation of surface heat and raises the temperature in the cities. The vegetation consists of urban greening, urban forests and green areas, have the function to minimize this effect. To reconcile these factors work aims to collect data on surface temperature by satellite images, LANDSAT 5 captured on 18/12/2012 point 75 e 76, orbits 221, band 6 and on-site survey with thermo-hygrometer, with possession of the data, crossing to the survey conducted vegetative and provide a management vision to improve the microclimate of the city under study. The remote sensing and the geographic information system allow the evaluation of different earth surface temperatures. The municipality reduced area and the low resolution detector used makes the temperature analyzes at the urban area more difficult requiring the use of other programs to assist in the data interpretation. The vegetation coverage at urban area directly affects in the temperature decreasing improving the urban micro-climate. The different analyzed surface coverage also affects the apparent temperature. Among the studied ranks, the eucalyptus cultivation and native forest rank show mild apparent temperature around 22.0°C and the solo exposed to the higher apparent temperature around 37.0°C. The 4,5 and 7 sectors present a 27,0°C temperature average, and these are the sectors with the milder temperature due to the vegetation coverage area. The temperatures difference at the 9, 10, 12 and 13 sectors from 32.0°C to 27.0°C is due to the existing green areas, such as squares. The site survey high temperatures measured by thermo-hygrometer are around 35.0°C due to...

Orientador: Sérgio Campos / Banca: Ellen Fitipaldi B. Carrega / Banca: Fernanda Leite Ribeiro / Resumo: Com a ocupação massiva da malha urbana e as atividades decorrentes do crescimento desordenado dessas áreas, ocorre uma alteração do clima urbano, tornando-o insalubre. Um dos fatores que contribui para a má qualidade de vida em decorrência deste fato são as ilhas de calor que consiste no acúmulo de calor na superfície e eleva a temperatura nas cidades. A vegetação urbana constituída de arborização urbana, bosques e áreas verdes, têm como função minimizar este efeito. Para conciliar esses fatores o trabalho tem como objetivo levantar os dados de temperatura de superfície através de imagens de satélite, LANDSAT 5 captada no dia 18/12/2012 dos pontos 75 e 76, órbita 221, banda 6 e levantamento in loco com termo-higrômetro, com posse dos dados, cruzar com o levantamento vegetativo realizado e proporcionar uma visão de gestão para melhorar o microclima do município em estudo. O sensoriamento remoto e o sistema de informação geográfica permitem a avaliação de diferentes temperaturas da superfície terrestre. A área reduzida do Município e a baixa resolução do sensor utilizado dificultaram a análise de temperatura da área urbana sendo necessário o uso de outros programas para auxiliar na interpretação de dados. A cobertura de vegetação na área urbana interfere diretamente na diminuição da temperatura melhorando o micro-clima urbano. As diferentes coberturas da superfície analisada também interferem na temperatura aparente. Entre as classes estudas a classe cultivo de eucalipto e mata nativa apresentaram temperatura aparente amena em torno de 22.0°C e o solo exposto a maior temperatura aparente entre 37.0°C. Os setores 4,5 e 7 apresentam uma média de temperatura de 27,0°C sendo os setores com temperatura mais amena devido a área de cobertura vegetal. A diferença de temperatura nos setores 9, 10, 12 e 13 de 32.0°C para 27.0°C é devido a existência de ... / Abstract: With the massive occupation of the urban and activities arising from the uncontrolled growth of these areas, a change occurs in the urban climate, making it unhealthy. One factor that contributes to poor quality of life due to this fact are the islands of heat which consists in the accumulation of surface heat and raises the temperature in the cities. The vegetation consists of urban greening, urban forests and green areas, have the function to minimize this effect. To reconcile these factors work aims to collect data on surface temperature by satellite images, LANDSAT 5 captured on 18/12/2012 point 75 e 76, orbits 221, band 6 and on-site survey with thermo-hygrometer, with possession of the data, crossing to the survey conducted vegetative and provide a management vision to improve the microclimate of the city under study. The remote sensing and the geographic information system allow the evaluation of different earth surface temperatures. The municipality reduced area and the low resolution detector used makes the temperature analyzes at the urban area more difficult requiring the use of other programs to assist in the data interpretation. The vegetation coverage at urban area directly affects in the temperature decreasing improving the urban micro-climate. The different analyzed surface coverage also affects the apparent temperature. Among the studied ranks, the eucalyptus cultivation and native forest rank show mild apparent temperature around 22.0°C and the solo exposed to the higher apparent temperature around 37.0°C. The 4,5 and 7 sectors present a 27,0°C temperature average, and these are the sectors with the milder temperature due to the vegetation coverage area. The temperatures difference at the 9, 10, 12 and 13 sectors from 32.0°C to 27.0°C is due to the existing green areas, such as squares. The site survey high temperatures measured by thermo-hygrometer are around 35.0°C due to... / Mestre

Orientador: Jurandir Zullo Junior / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agrícola / Made available in DSpace on 2018-08-22T19:23:28Z (GMT). No. of bitstreams: 1 Lazarim_CamilaGiorgi_M.pdf: 45631852 bytes, checksum: 657cbb93f5038306a09d246ea6a15804 (MD5) Previous issue date: 2013 / Resumo: A obtenção de valores precisos e confiáveis, em uma quantidade adequada, e com a maior agilidade possível da temperatura da superfície terrestre é estratégica para aplicações de grande interesse como os estudos de mudanças climáticas e o monitoramento agrometeorólogico. As redes meteorológicas de superfície, automáticas e manuais, são de grande utilidade e imprescindíveis, mas, normalmente, apresentam limitações que dificultam a sua utilização efetiva e confiável em escala regional, tais como: i) Distribuição espacial inadequada; ii) Grande diversidade de equipamentos para medidas; iii) Difíceis condições de manutenção e acesso a dados. Os dados provenientes dos sensores remotos, a bordo dos satélites orbitais, representam uma alternativa que deve ser considerada visando o aumento da densidade, confiabilidade e agilidade de obtenção dos dados de temperatura da superfície terrestre em estudos regionais. A estimativa da evapotranspiração é um parâmetro de grande importância no monitoramento da irrigação, na simulação de balanços hídricos, no acompanhamento do desenvolvimento e produção de uma cultura agrícola, e em estudos climáticos. A utilização da temperatura de superfície como dado inicial simplifica os modelos de estimativa de evapotranspiração de uma determinada área de interesse. Esse é o caso do método S-SEBI (Simplified Surface Energy Balance Index), que se fundamenta no fluxo de calor entre a superfície do solo e a atmosfera. Sendo assim, o objetivo desse trabalho foi estimar a evapotranspiração, através do algoritmo S-SEBI, e a temperatura de superfície, utilizando um modelo adaptado dos algoritmos propostos por Sobrino et al. (1997) e Ulivieri et al. (1994) modificados por Ouaidrari et al. (2002). Isto foi feito através da avaliação do comportamento dessas equações propostas ao longo do ano, modificando constantes e dados de entrada, visando à utilização efetiva delas no monitoramento agrometeorológico. Assim, foi obtida uma equação adaptada que teve resultados significativos na estimativa da temperatura de superfície e, a partir desse dado, foi estimada a evapotranspiração que apresentou valores superestimados / Abstract: Obtaining accurate and reliable Earth's surface temperature values, adequate in quantity and with the greatest flexibility possible is of great strategic interest for applications such as studies of climate change and agrometeorological monitoring. The surface meteorological networks - both automatic and manual - are very useful and indispensable, but often have limitations that hinder their effective and reliable use in regional scale, such as: i) inadequate spatial distribution, ii) Wide range of equipment iii) Conditions of maintenance and data access. Data coming from remote sensors on board orbiting satellites represent an alternative that should be considered in order to increase the density, reliability and speed of data attainment from surface temperature in regional studies. The evapotranspiration is a parameter of great importance in monitoring the irrigation and the development and production of a crop, the water balance simulation, and climate studies. The use of surface temperature as initial data simplifies the models that estimate hourly and daily evapotranspiration for a certain area of interest. This is the case of the method SEBI S-(Simplified Surface Energy Balance Index), which is based on the heat flux between the ground surface and the atmosphere. Therefore, the objective of this work was to estimate the evapotranspiration through the S-SEBI algorithm and the surface temperature, using a model adapted from the algorithms proposed by Sobrino et al. (1997) and Ulivieri et al. (1994) modified by Ouaidrari et al. (2002). This was done by evaluating their behavior of these proposed equations over the year and modifying the constants and the input data, for their effective use in agrometeorological monitoring. Therefore, was obtained an equation adapted which had significant results in the estimated surface temperature and, from this data was estimated the evapotranspiration which presented overestimated values / Mestrado / Planejamento e Desenvolvimento Rural Sustentável / Mestra em Engenharia Agrícola

In satellite communications, non-linear interference is created by the non-linear power amplifier aboard the satellite. Even in the case of a memoryless power amplifier, the channel is a non-linear system with memory due to the presence of linear filters on ground and aboard the satellite. The non-linear interference degrades the system performance, especially when considering high-order modulations or in case of several signals being amplified by the same power amplifier. In this thesis, we have proposed algorithms at the transmitter and at the receiver to digitally compensate this interference. In particular, a new predistortion algorithm has been proposed, which significantly improves state-of-the-art algorithms. Since the complexity of this algorithm is an issue, low-complexity algorithms have also been proposed and achieve almost the same performance as the initial algorithm. We have also proposed joint predistortion and turbo-equalization algorithms to further improve the system performance. / En communications par satellite, de l’interférence non-linéaire est créée par l’amplificateur de puissance non-linéaire à bord du satellite. Même si l’amplificateur peut être considéré comme sans mémoire, le canal est malgré tout un système non-linéaire avec mémoire de par la présence de filtres linéaires au sol ou à bord du satellite. L'interférence non-linéaire dégrade les performances du système, en particulier lorsqu’on considère des modulations d’ordre élevé ou plusieurs signaux amplifiés par le même amplificateur de puissance. Dans cette thèse, nous avons proposé des algorithmes à l’émetteur et au récepteur pour compenser numériquement cette interférence. En particulier, nous avons proposé un nouvel algorithme de prédistorsion qui améliore de façon significative les algorithmes de l’état-de-l’art. La complexité de l’algorithme étant très élevée, nous avons proposé des algorithmes de plus faible complexité atteignant pratiquement les mêmes performances par rapport à l’algorithme initial. Nous avons aussi proposé des algorithmes de prédistorsion et d’égalisation conjointes, permettant d'atteindre des performances plus élevées qu'avec la prédistorsion seule. / Doctorat en Sciences de l'ingénieur / info:eu-repo/semantics/nonPublished

Orientador: Hélio Grassi Filho / Coorientador: Célia Regina Zimback / Banca: Maria Helena Moraes Spinelli / Banca: Paulo Milton Barbosa Landim / Banca: Diego Augusto de Campos Moraes / Banca: Aline Azevedo Narario / Resumo: A atual demanda por informações precisas e de baixo custo de obtenção causa um aumento na procura por serviços remotos, como o geoprocessamento, a geoestatística e o aprendizado de máquinas. Este trabalho objetiva a obtenção de informações relacionadas a leituras de teores de clorofila, a partir de um banco de dados de campo e por imagens de satélite aplicadas a uma área de cultivo de aveia preta, com baixos custos. Com um banco de dados preciso sobre o teor de clorofila, acredita-se ser possível reduzir custos na implantação e execução de sistemas de irrigação. Diversos autores já realizaram a comparação entre o teor de clorofila e a disponibilidade de água e outros já pontuaram o grande benefício da irrigação sobre diversos cultivares. Com a hipótese de que é possível através da utilização de técnicas de baixo custo a obtenção de valores de teor de clorofila, o trabalho utilizou de técnicas de geoestatística para procurar uma correlação entre os dados físicos e os índices de vegetação gerados a partir de imagens do satélite Landsat 5. Ao encontrar resultados insatisfatórios, partiu-se para um estudo dos dados em treinamento de máquinas e mineração de dados. Após passar por vários processos, o algoritmo Gradient Boosting Machine (GBM) possibilitou a geração de uma imagem com valores estimados clorofila bastante semelhante aos reais obtidos em campo. / Abstract: The nowadays demand for accurate and low-cost obtained information has increased the demand for remote services, such as geoprocessing, geostatistics and machine learning. This work aims to increase the accuracy of information related to readings of chlorophyll content from a field database and satellite images, applied to a black oat growing area. With a precise database on chlorophyll content, it is believed that it is possible to reduce costs in the implementation and execution of irrigation systems. Several authors have already made the comparison between chlorophyll content and water availability and others have already pointed out the great benefit of irrigation on several cultivars. With the hypothesis that is possible through the use of low cost techniques the obtaining values of chlorophyll content, the work used geostatistics techniques to search for a correlation between the physical data and the vegetation indexes generated from images of Landsat 5 satellite .When finding unsatisfactory results, we started with a study of data in machine training and data mining. And after passing through several processes, the Gradient Boosting Machine (GBM) algorithm allowed the generation of an image with estimated chlorophyll values very similar to those obtained in the field. / Doutor

Satellite systems are being planned for two-way communication with mobile vehicles using UHF and L-band frequencies. Of special concern in the system design are the characteristics of propagation in suburban and rural areas where fading occurs due to multipath effects and vegetative shadowing. A review of the literature was performed to study these propagation impairments. Available experimental data are examined, compared, and summarized. Propagation through vegetation is studied in order to compare reported modeling efforts and to determine the parameter dependences of path loss. A simple deterministic path model is then presented to estimate vegetative path loss. An overall statistical model is also proposed to describe the signal level fading statistics. The statistical model is compared to data, and the deterministic path model is used to determine the mean of signal level distribution functions in the presence of shadowing. / Master of Science

Fade and inter-fade duration data obtained from the three beacons at 12, 20, and 30 GHz aboard the OLYMPUS satellite were analyzed. The different types of signal impairments and their causes were highlighted and a literature survey conducted. Twelve months of fade and inter-fade data were analyzed and the results of these statistics are presented in the form of tables and figures. The analysis was done on both the monthly and annual data. These tables and figures show that at the higher fade levels, the number of fade events and the fade time is smaller than at the lower thresholds. For the same fade level the number of fade events and the fade time goes down as the fade duration which it exceeds is increased. Inter-fade durations also showed similar results. The fades exhibited seasonal dependencies. The number of fades (and consequently the fade time) were much higher for the months of May through August and for the months of March and December. The other months showed very little fade activity. A model was also constructed that can predict the fade time as a function of frequency, attenuation level, and fade duration interval. The predicted fade times agree well with the measured fade duration data. An alternate simplified version of the model is also presented. / Master of Science

Frequency scaling of attenuation is the prediction of attenuation at a desired frequency from attenuation values at a base frequency. The attenuation at the base frequency is often known from prior measurements. Frequency scaling of attenuation is of interest because of the eventual need to exploit higher frequency bands. Most satellite communications traffic now use C-band (4-8 GHz) and Ku-band (12-18 GHz). The next approved, yet largely unused, frequency allocation for domestic use is in the K-band (18-27 GHz) to Ka-band (27-40 GHz). At these higher frequencies, however, earth-space radio links suffer atmospherically induced impairments as frequency increases. In particular, rain causes severe fading. Consequently, satellite systems in these higher bands are very susceptible to outages due to rain-induced fades. Reliable frequency scaling models are needed in system design to estimate the effect of these rain-induced fades. Between August 1990 and August 1992, V.P.I. & S.U.'s SATCOM Group performed extensive measurements of slant path attenuation using the 12, 20, and 30 GHz beacon signals (in the Ku/Ka-bands) of the European OLYMPUS experimental satellite. The experimental results are used to evaluate the usefulness of scaling models proposed by other researchers, both for instantaneous and statistical purposes. New models are presented for accurate scaling of attenuation within the Ku/Ka-bands. / Master of Science

This thesis reports the results of a thorough study into the effects of rain and ice on the polarization reuse technique for earth-space communications. Precipitation in the form of rain and ice leads to significant depolarization and attenuation of dual polarized signals above about 10 GHz. The depolarization versus attenuation relationship is examined in depth using a rigorous multiple scattering model. This relationship for rain is expressed in the form of a simple function similar to that used by the CCIR. Prediction accuracy using this simple model is quantified by comparisons to measured data and other model values. The impact of depolarization effects on the carrier-to-noise ratio for digital PSK systems is also addressed. Preliminary results for ice layer effects are presented. / Master of Science

Thesis (M.S.)--Air Force Institute of Technology, 2003. / Title from title screen (viewed July 1, 2004). "March 2003." Vita. "AFIT/GCA/ENV/03-04." "ADA415257"--URL. Includes bibliographical references (p. 71-74). Also issued in paper format.