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Sensoriamento remoto na identificação de elementos e tipologias urbanas relacionados à ocorrência da leptospirose no subúrbio ferroviário de Salvador, Bahia. / Using remote sensing to identify urban elements and patterns related to Leptospirosis occurrence at the Railroad Suburb of Salvador, Brazil.Brito, Patrícia Lustosa 17 May 2010 (has links)
Em países em desenvolvimento, doenças infecciosas se constituem ainda um grave problema de saúde pública. Muitas vezes, essas doenças estão altamente relacionadas a condições urbanas que podem ser encontradas em áreas mais pobres. Nesses casos, o sensoriamento remoto (SR) pode ser utilizado como uma poderosa ferramenta de estudo. Novos produtos de SR se encontram disponíveis no mercado, permitindo o desenvolvimento de análises espaciais cada vez mais profundas e precisas. No entanto, a complexidade que envolve a epidemiologia de doenças, a irregularidade de ocupações urbanas e a heterogeneidade das imagens de alta resolução espacial têm restringido o desenvolvimento de estudos nesse campo científico. O desafio de identificar elementos e tipologias urbanas em imagens de sensoriamento remoto relacionadas à ocorrência da leptospirose justifica-se pela crença de que ferramentas de SR podem ser mais amplamente utilizadas no monitoramento de carências urbanísticas e, consequentemente, na gestão de ações e investimentos públicos. A metodologia contempla uma revisão bibliográfica sistemática, com base na qual foram criados modelos de transmissão da leptospirose e investigadas tipologias urbanas presentes na área de estudo. As variáveis baseadas em dados de SR que formam os indicadores dos modelos e que caracterizam as tipologias foram usadas para definir objetos e atributos, alvos das investigações em imagens de alta resolução espacial. Os procedimentos de SR adotados baseiam-se na segmentação multi-nível, classificação baseada em objeto, e utilizam ortofotografias aéreas, imagem QuickBird e base cartográfica do eixo viário do Subúrbio Ferroviário de Salvador. Para o cálculo das variáveis utilizou-se produtos do processamento da imagem QuickBird. Procedimentos de geoprocessamento foram realizados em sistema de informações geográficas. Por fim, realizaram-se as primeiras análises epidemiológicas que investigam a relação da leptospirose com os elementos e tipologias urbanas identificados por meio de SR, cujos resultados apontam maior influência do percentual de pavimentação das vias, sua largura e qualidade da edificação na possibilidade de ocorrência da leptospirose no Subúrbio. Possíveis fontes de viés são discutidas ao lado de propostas de continuação da pesquisa. Apesar dos problemas e limitações identificados no processo, o estudo mostra que a metodologia desenvolvida baseada em SR se constitui uma poderosa ferramenta de análise do espaço intra-urbano, uma vez que permite a identificação de elementos e tipologias relacionados a situações de risco, apoiando assim, o direcionamento de investimentos públicos que venham refletir na melhoria das condições de saúde da população. / In developing countries, infectious diseases are still a serious public health problem. These diseases are often and highly related to urban conditions found in poor areas, in these cases, remote sensing (RS) can be used as a powerful tool. New RS products are now available allowing the development of more complex and precise spatial analysis. On the other hand, the complexity of epidemiological studies, the lack of regularity of precarious urban settlements and the heterogeneity of high spatial resolution images have been restricting the development of studies in this areas. The challenge of identifying urban elements and typologies related to the leptospirosis using RS products is pursued due the belief that RS can be more used among professionals and researchers in the task of monitoring the urban environment, and directing public investments and actions. The methodology presented consists in a broad literature review, which was used to support leptospirosis transmission risk models and to find urban typologies at the study area. Variables based on RS were identified in the disease models and in the typologies characterization. This models and typologies also defined targets to look for in the high spatial resolution images. RS procedures were based on multi-level segmentation, object-based classification, aerial photography, QuickBird satellite images and street axis vector data of the Railroad Suburb of Salvador. In order to obtain the variable\'s values, results of QuickBird image processing were added to a geographic database and processed using vector and raster over layering techniques. At last, epidemiological analysis were initiated aiming to find its relationship with the urban elements and typologies identified using RS. The results points paved streets, streets wideness and house quality as the RS variables that have more influence on the leptospirosis transmission chance. The dissertation also presents research restrains, potentials, possible sources of bias and future studies proposals. It concludes that the RS based methodology presented is a powerful tool for urban analysis, due to its capabilities for identifying urban targets related to risky situations, and, therefore, for helping direct public investments to improve life conditions an unprivileged city areas.
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Sensoriamento remoto na identificação de elementos e tipologias urbanas relacionados à ocorrência da leptospirose no subúrbio ferroviário de Salvador, Bahia. / Using remote sensing to identify urban elements and patterns related to Leptospirosis occurrence at the Railroad Suburb of Salvador, Brazil.Patrícia Lustosa Brito 17 May 2010 (has links)
Em países em desenvolvimento, doenças infecciosas se constituem ainda um grave problema de saúde pública. Muitas vezes, essas doenças estão altamente relacionadas a condições urbanas que podem ser encontradas em áreas mais pobres. Nesses casos, o sensoriamento remoto (SR) pode ser utilizado como uma poderosa ferramenta de estudo. Novos produtos de SR se encontram disponíveis no mercado, permitindo o desenvolvimento de análises espaciais cada vez mais profundas e precisas. No entanto, a complexidade que envolve a epidemiologia de doenças, a irregularidade de ocupações urbanas e a heterogeneidade das imagens de alta resolução espacial têm restringido o desenvolvimento de estudos nesse campo científico. O desafio de identificar elementos e tipologias urbanas em imagens de sensoriamento remoto relacionadas à ocorrência da leptospirose justifica-se pela crença de que ferramentas de SR podem ser mais amplamente utilizadas no monitoramento de carências urbanísticas e, consequentemente, na gestão de ações e investimentos públicos. A metodologia contempla uma revisão bibliográfica sistemática, com base na qual foram criados modelos de transmissão da leptospirose e investigadas tipologias urbanas presentes na área de estudo. As variáveis baseadas em dados de SR que formam os indicadores dos modelos e que caracterizam as tipologias foram usadas para definir objetos e atributos, alvos das investigações em imagens de alta resolução espacial. Os procedimentos de SR adotados baseiam-se na segmentação multi-nível, classificação baseada em objeto, e utilizam ortofotografias aéreas, imagem QuickBird e base cartográfica do eixo viário do Subúrbio Ferroviário de Salvador. Para o cálculo das variáveis utilizou-se produtos do processamento da imagem QuickBird. Procedimentos de geoprocessamento foram realizados em sistema de informações geográficas. Por fim, realizaram-se as primeiras análises epidemiológicas que investigam a relação da leptospirose com os elementos e tipologias urbanas identificados por meio de SR, cujos resultados apontam maior influência do percentual de pavimentação das vias, sua largura e qualidade da edificação na possibilidade de ocorrência da leptospirose no Subúrbio. Possíveis fontes de viés são discutidas ao lado de propostas de continuação da pesquisa. Apesar dos problemas e limitações identificados no processo, o estudo mostra que a metodologia desenvolvida baseada em SR se constitui uma poderosa ferramenta de análise do espaço intra-urbano, uma vez que permite a identificação de elementos e tipologias relacionados a situações de risco, apoiando assim, o direcionamento de investimentos públicos que venham refletir na melhoria das condições de saúde da população. / In developing countries, infectious diseases are still a serious public health problem. These diseases are often and highly related to urban conditions found in poor areas, in these cases, remote sensing (RS) can be used as a powerful tool. New RS products are now available allowing the development of more complex and precise spatial analysis. On the other hand, the complexity of epidemiological studies, the lack of regularity of precarious urban settlements and the heterogeneity of high spatial resolution images have been restricting the development of studies in this areas. The challenge of identifying urban elements and typologies related to the leptospirosis using RS products is pursued due the belief that RS can be more used among professionals and researchers in the task of monitoring the urban environment, and directing public investments and actions. The methodology presented consists in a broad literature review, which was used to support leptospirosis transmission risk models and to find urban typologies at the study area. Variables based on RS were identified in the disease models and in the typologies characterization. This models and typologies also defined targets to look for in the high spatial resolution images. RS procedures were based on multi-level segmentation, object-based classification, aerial photography, QuickBird satellite images and street axis vector data of the Railroad Suburb of Salvador. In order to obtain the variable\'s values, results of QuickBird image processing were added to a geographic database and processed using vector and raster over layering techniques. At last, epidemiological analysis were initiated aiming to find its relationship with the urban elements and typologies identified using RS. The results points paved streets, streets wideness and house quality as the RS variables that have more influence on the leptospirosis transmission chance. The dissertation also presents research restrains, potentials, possible sources of bias and future studies proposals. It concludes that the RS based methodology presented is a powerful tool for urban analysis, due to its capabilities for identifying urban targets related to risky situations, and, therefore, for helping direct public investments to improve life conditions an unprivileged city areas.
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Using high resolution satellite imagery to map aquatic macrophytes on multiple lakes in northern Indiana /Gidley, Susan Lee. January 2009 (has links)
Thesis (M.S.)--Indiana University, 2009. / Department of Geography, Indiana University-Purdue University Indianapolis (IUPUI). Advisor(s): Jeffrey S. Wilson, Lenore P. Tedesco, Daniel P. Johnson. Includes vitae. Includes bibliographical references (leaves 71-77).
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Bathymetry, substratum and emergent vegetation distributions during an extreme flood event in Delta Marsh, ManitobaGeard, Nola 25 September 2015 (has links)
In 2011 Manitoba experienced an extreme flood. The operation of the Assiniboine River Diversion resulted in the addition of approximately 1.72 million cubic decameters of water to Lake Manitoba and an increase in water levels to 1.5 m above normal. Although this event resulted damage to farmland and many local homes, it also provided me the unique opportunity to utilize previously impractical methods of bathymetric and substrata distribution analysis in the adjoining Delta Marsh. Combined with satellite imagery taken in 2011 I was able to classify the vegetation classes within the study area and explore the relationship between vegetation distributions and water depth as well as those between water depth and substrata distribution. A seed bank study was carried out to explore the diversity of viable seeds in the area. In addition, satellite imagery taken in 2009 was used to evaluate the effects of the flood event experienced in 2011. / October 2015
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Comparison Of Different Spatial Resolution Images For Polygon-based Crop MappingOzdarici, Asli 01 September 2005 (has links) (PDF)
Polygon-based classification applied on the unitemporal SPOT4 XS, SPOT5 XS, IKONOS XS, QuickBird XS and QuickBird Pansharpaned (PS) images is described. The study site is an agricultural area located near Karacabey, Turkey covering an area of about 95 km2. The objective was to assess the effect of the spatial resolution on the polygon-based classification of agricultural crops. Both the post-polygon and pre-polygon classifications were carried out. In the post-polygon classification, first, the images were classified on per-pixel basis through a Maximum Likelihood classifier. Then, for each field, the model class was computed and the field was assigned the label of the model class. In the pre-polygon classification, first, the mean values were calculated for each field. Then, the per-pixel Maximum Likelihood Classification was carried out using the mean bands.
The post-polygon classification of the SPOT4 XS and SPOT5 XS images produced an overall accuracy of 76,1% and 81,4%, respectively. The IKONOS XS image provided the highest overall accuracy of 88,6%. On the other hand, the QuickBird XS and QuickBird PS images provided the overall accuracies of 83,7% and 85,8%, respectively. For the pre-polygon classification, the overall accuracies of the SPOT4 XS and SPOT5 XS images were computed to be 65,2% and 69,8%, respectively. Similar to the post-polygon classification, the IKONOS image provided the highest overall accuracy of 81,8% while the SPOT5 XS image revealed slightly better results than the SPOT4 XS image. The overall accuracies of the QuickBird XS and PS images were found to be 78,6% and 82,1%, respectively.
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Integrating Field and Remotely Sensed Data for Assessment of Coral Reef and Seagrass HabitatsChris Roelfsema Unknown Date (has links)
Coral reef habitats are being threatened by global warming, natural disasters and the increased pressure of the global population. These habitats are in urgent need of efficient monitoring and management programs to sustain their biological, economic and cultural values for the global community. Habitats maps, describing the extent, composition and the condition of the benthos in time and space, form a valuable information source for scientists and managers to answer their management questions. Adequate and accurate habitat maps are needed and can be provided by a range of mapping approaches, which are based on integration of field and remotely sensed image data sets. Scientists, technicians and managers lack knowledge on the cost effectiveness and procedures for calibrating and validating mapping approaches that integratef field data and remote sensing imagery, for use in various coral reef and seagrass environments. This knowledge is required to adequately design, apply and assess operational mapping approaches and their maps. Hence, the aim of this study is to improve habitat mapping capabilities by integrating low cost remote sensing approaches and field-calibration and -validation methods for a range of coral reef and seagrass environments. To achieve this aim, commonly used habitat mapping approaches that integrated field-calibration and -validation methods with remote sensing image based processing techniques were studied, in different coral reef and seagrass environments in Fiji and Australia. These environments varied in: water clarity, water depth, benthic composition, spatial complexity of benthic features, and remoteness. The study had three objectives: (1) to evaluate the accuracy, cost and perceived relevance of eight commonly used benthic cover mapping approaches for three different coral reef environments. (2) Conduct a cost-benefit comparison of two field survey methods for calibrating and validating maps of coral reef benthos derived from high-spatial resolution satellite images in three different coral reef environments. (3) Identify considerations for comparing the thematic accuracy of multi-use image based habitat maps in various coral reef and seagrass environments. A scientific assessment and an evaluation of the relevance for managers, was conducted on eight commonly used habitat mapping approaches for three different coral reef environments. This analysis revealed a preference for a mapping approach based on supervised classification of Quickbird imagery integrated with basic field data. This approach produced an accurate map within a short time with low cost in that suited the user’s purpose. Additionally, the results indicated that user preference in selecting a suitable map was affected by: variations in environmental complexity; map purpose, and resource management requirements. To assess the variation in performance of methods for calibration and validation for coral reef benthic community maps, derived from high-spatial resolution satellite images, a comparison was conducted between spot check and georeferenced photo-transect based mapping approaches. The assessment found that the transect based method was a robust procedure which could be used in a range of coral reef environments to map the benthic communities accurately. In contrast, the spot check method is a fast and low cost approach suitable to map benthic communities which have lower spatial complexity. However, the spot check approach provides robust results, if it is applied in a standardised manner, providing a description of selected homogenous areas with georeferenced benthic cover photos. Considerations for comparing the thematic accuracy of multi-use image based habitat maps in various coral reef and seagrass environments were assessed. This included a review of 80 scientific publications on coral reef and seagrass habitat mapping, which revealed a lack of knowledge and reporting in regards to the assessment of the thematic map accuracy. These publications commonly used thematic accuracy measures and factors controlling their variation were then determined for various habitat mapping approaches for different coral reefs and seagrass environments. Assessment of these measures found that variations in accuracy levels were not only a result of actual differences in map accuracy, but were also due to: spatial complexity of benthic features present in the study area; distribution of the calibration and validation samples relative to each other, and the level of detail provided by these samples. Two main outcomes resulted from this dissertation. The first was the development of a robust mapping approach based on georeferenced photo-transect method integrated with high spatial resolution imagery, which is able to accurately map a variety of coral reef and seagrass habitats. The second outcome is an increase in capacity for coral reef and seagrass habitat mapping by scientists and managers. This increase is accomplished by providing knowledge on various habitat mapping approaches in regards to their: cost/time, accuracy and user relevance; performance of calibration and validation field methods; and performance of accuracy measures, when applied in a range of coral reef and seagrass environments. The findings and outcomes from this dissertation will significantly contribute to management of coral reef and seagrass environments by enabling scientists and managers to choose appropriate combinations of: field and image data sources; processing approaches, and validation methods for habitat mapping in these environments.
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Caracterização fisiográfica e de alguns atributos físicos e químicos dos solos da microbacia Jardim Novo Horizonte, em Ilha Solteira, SP /Queiroz, Hernandes Andrade. January 2008 (has links)
Resumo: É inquestionável a degradação de mananciais devido à erosão e a poluição, decorrentes do desenvolvimento econômico. Estes fatos são caracterizados pelo mau planejamento dos recursos naturais, tanto em propriedades isoladas como nas microbacias. Como conseqüência, o impacto sócio-ambiental atraído pelos problemas de poluição e acúmulo de macrofitas e assoreamento das microbacias, leva a própria destruição da drenagem. Neste sentido este trabalho teve como objetivos caracterizar a fisiografia e alguns atributos físicos e químicos dos principais solos de uma microbacia na cidade de Ilha Solteira, São Paulo. Este estudo dará subsídios para a identificação de áreas de riscos quanto à erosão e poluição dos mananciais de água e do atual estágio de degradação dos solos que compõem a microbacia. Foram utilizadas imagens de satélite de alta resolução 0,6 m Quickbird e o programa SPRING versão 4.3 para caracterização fisiográfica da microbacia e mapeamento dos solos. Utilizando a metodologia de topossequência em relação a vertente, em 5 transetos com pontos locados no sentido do espigão até a foz, foram realizadas coletas de amostras de solo para análise granulométrica, macroporosidade, microporosidade, porosidade total, pH, matéria orgânica, fósforo e cátions trocáveis, em duas profundidades (0,00-0,10 e 0,10-0,20 m). Também foi realizada a medição da taxa de infiltração de água do solo. Realizou-se a estatística descritiva para a análise dos resultados encontrados. Os solos representativos da microbacia estudada foram: Latossolo Vermelho distrófico e Argissolo Vermelho- Amarelo eutrófico; a Microbacia do Jardim Novo Horizonte apresenta relevo com cotas que variam de 280 a 370 m, rede de drenagem dendrítica e a ocupação mais representativa da área é com pastagem; o Latossolo Vermelho apresentou-se com condições físicas mais... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: There is no doubt the fountain degradation of due to erosion and pollution resulting from economic development. These facts are characterized by poor planning of natural resources, both in individual properties as in watersheds. In consequence the social and environmental impact attracted the problems with pollution and accumulation of macrophytes and silting of watersheds, leads the very destruction of drainage. The work aimed to characterize the physiography, some physical and chemical attributes from the mains soils of a watershed the city of Ilha Solteira, São Paulo, Brazil. This study will provide subsidies for the identification areas of risk as to erosion and pollution of water sources and the current stage of degradation that make up the watershed. Satellite imagery was use of high-resolution 0.6 m Quickbird and the program SPRING version 4.3 for physiographic characterization of watershed mapping of soils. Using the methodology of topography regarding instance, on 5 points with transect leased to the jetty to the mouth, were made of soil samples for analysis texture, macro, micro and total porosity, pH, organic matter, P e exchangeable cations, in two depths (0.00-0.10 and 0.10-0.20 m). It was also performed to measure the soil water infiltration. There was the descriptive statistics for the analysis of findings. The representative soil were: Oxisol and Alfisol; the altitude variation was 280 to 370 m, the drainage type is dendritica and the more soil use is with pasture; the physical conditions were more deteriorated in Oxisol when use the water infiltration rate quality indicator; the physical conditions for Alfisol were better in areas planted with tree species, compared with horticulture; the physical and chemical attributes variability were higher in the Oxisol compared to Alfisol. / Orientador: Marlene Cristina Alves / Coorientador: Hélio Ricardo Silva / Banca: Elizete Aparecida Checon de Freitas Lima / Banca: Arnaldo Yoso Sakamoto / Mestre
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Uso de imagens de alta e media resolução espacial no estudo de areas cafeeiras / Use of high and medium spatial resolution images in the study of coffee areasRamirez, Glaucia Miranda 13 August 2018 (has links)
Orientador: Jurandir Zullo Junior / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Engenharia Agricola / Made available in DSpace on 2018-08-13T05:57:27Z (GMT). No. of bitstreams: 1
Ramirez_GlauciaMiranda_D.pdf: 28885401 bytes, checksum: 676ec9c1c9823ae7accd5e51d3de1035 (MD5)
Previous issue date: 2009 / Resumo: O café sempre foi sinônimo de progresso e contribuiu de maneira decisiva para a industrialização do Brasil sendo, ainda hoje, um dos seus produtos agrícolas mais importantes. A obtenção de informações precisas, em tempo hábil e com baixo custo, sobre a extensão e o rendimento da cultura, são instrumentos valiosos para um planejamento adequado da cultura no país. Dentre as técnicas que podem ser utilizadas, neste caso, o sensoriamento remoto é uma das que possuem um grande potencial de aplicação, principalmente considerando o aumento da disponibilidade de imagens de média resolução espacial e o advento das imagens de alta resolução espacial. Sendo assim, o objetivo geral do trabalho foi compreender as interações existentes entre os parâmetros biofísicos de cafezais e a resposta espectral registrada nas bandas de imagens dos satélites TM/LANDSAT e QUICKBIRD adquiridas em 24/01/2006 e 05/02/2006, respectivamente. Foram utilizados 30 talhões pertencentes a seis propriedades agrícolas, localizadas na região da Alta Mogiana, em São Paulo, entre os municípios de Ribeirão Corrente, Franca e Cristais Paulista. Os parâmetros biofísicos da cultura determinados a partir de dados de campo foram o espaçamento entre linhas e plantas, altura, IAF, diâmetro da copa, porcentagem de cobertura vegetal, rugosidade, variedade e biomassa. Foram utilizados valores de refletância real das bandas espectrais dos dois satélites e quatro índices de vegetação (NDVI, GVI, SAVI e RVI). Foi aplicado o teste de Tukey e realizadas análises de correlação, regressão e fatorial por componentes principais, utilizando os dados biofísicos e remotos disponíveis. Alguns parâmetros biofísicos não puderam ser estimados, mesmo com a melhoria da resolução espacial. Outros foram estimados (IAF, Biomassa e Altura) mesmo utilizando dados remotos de média resolução espacial. A análise de componentes principais permitiu separar plantios em produção, de áreas em formação, para as duas imagens, sendo que a associação dos parâmetros biofísicos "porcentagem de cobertura" e "densidade populacional" foi a principal responsável por estes resultados. Estes agrupamentos podem ser de grande utilidade na classificação automática de imagens. Apesar do avanço tecnológico proporcionado pelas imagens de alta resolução espacial, elas não se mostraram superiores a ponto de substituírem, mas complementarem as informações fornecidas pelas imagens de média resolução. / Abstract: Coffee has been synonymous of progress and has strongly contributed to the industrialization of Brazil. Nowadays, the coffee is still one of the most important Brazilian agricultural products. Precise, on time and low cost information about coffee area and yield are valuable tools for the crop planning in the country. For this purpose, remote sensing techniques show a great potential to be applied, especially considering the increased availability of medium spatial resolution images and the coming of high spatial resolution imagery. Thus, the main objective of this study was to understand the interactions between the biophysical parameters of coffee crops and the spectral response measured by the TM/LANDSAT and QUICKBIRD satellites spectral bands, acquired on 24/01/2006 and 05/02/2006, respectively. We used 30 coffee areas in six farms, located in the region of Alta Mogiana, in the State of São Paulo, between the municipalities Ribeirão Corrente, Franca e Cristais Paulista. The biophysical crop parameters determined from the field survey were the row and plants spacing, height, LAI, crown diameter, percentage of vegetation cover, roughness, variety and biomass. We used real values of reflectance from the spectral bands of both satellites and four vegetation indexes (NDVI, GVI, SAVI and RVI). Tukey test was applied and it was carried out the analysis of correlation, regression and factorial analysis through principal components by using the available remote and biophysical data. Some biophysical parameters could not be estimated, even with improved spatial resolution. Others were estimated (LAI, biomass and height), even using remote data of medium spatial resolution. The analysis of the main components allowed to separate crop lands in production and in formation in the two images. The combination of biophysical parameters "percentage of coverage" and "density" was the main responsible for these results. This technique can be very useful in the automatic classification of images. Despite the technological advances provided by the images of high spatial resolution, these images may not replace, but complement the information provided by medium-resolution images. / Doutorado / Planejamento e Desenvolvimento Rural Sustentável / Doutor em Engenharia Agrícola
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Multi angle imaging with spectral remote sensing for scene classificationPrasert, Sunyaruk 03 1900 (has links)
Approved for public release, distribution is unlimited / ine discrimination of similar soil classes was produced by the BRDF variations in the high-spatial resolution panchromatic image. Texture analysis results depended on the directionality of the gray level co-occurrence matrix (GLCM) calculation. Combining the different modalities of analysis did not improve the overall classification, perhaps illustrating the consequences of the Hughes paradox (Hughes, 1968) / Flight Lieutenant, Royal Thai Air Force
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Confrontation des données de terrain et de l'imagerie multi-sources pour la compréhension de la dynamique des mouvements de versantsKasperski, Johan 08 February 2008 (has links) (PDF)
Face aux menaces des grands mouvements de versants rocheux, les techniques conventionnelles de suivi ne fournissent pas une vision globale, contrairement aux techniques d'imagerie. En considérant leurs apports à la description cinématique de trois sites instables, nous montrons que (1) la corrélation d'images aériennes est une solution rapide pour une connaissance globale et multi-temporelle ; que (2) le scanner-laser terrestre apporte des informations sur les zones tourmentées et difficiles d'observation mais de manière limitée spatialement ; que (3) l'utilisation des images satellitaires haute résolution est encore inadaptée, et enfin (4) que les images terrestres de face constituent un moyen rapide, efficace et peu onéreux de suivi de sites. Concernant les sites choisis, nous montrons que le mouvement de versant de Sedrun (Suisse) subit un ralentissement constant depuis 2002 qui fait suite à une augmentation des vitesses de 150% à partir de 1990. La description précise de la cinématique, alliée à la géologie de terrain, renseigne quant à ses évolutions possibles. La zone frontale du site de Séchilienne (Isère) se translate plus qu'elle ne s'affaisse ; par les acquisitions du scanner-laser, nous démontrons la rotation vers l'aval de ses compartiments structuraux. Enfin, le site du tunnel des Cliets (gorges de l'Arly) subit une décompression difficilement visible par imagerie. Finalement, nous proposons un "guide" aux techniques d'imagerie applicables à l'auscultation de versant instable, en fonction des configurations de terrain. Enfin, l'imagerie a montré tout son potentiel et sa complémentarité avec les techniques conventionnelles de suivi des mouvements de versants.
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