149 resultados para Remote sensing images
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The analysis of natural processes, such as landslides, has a great importance for the prevention of accidents in pipelines, since it might compromise its security, with serious social and environmental implications. Considering the large territorial dimensions that pipelines can reach, remote sensing tools have great applicability for data acquisition, allowing the analysis of large areas in regular time periods. This study aims to analyze the relations between the occurrence of landslides and its natural conditionings, on a stretch of the ORBEL pipeline, in the municipalities of Duque de Caxias, Nova Iguaçu and Belford Roxo – Rio de Janeiro. GeoEye sensor system images were used with spatial resolution of 0.5 m, from November/2009, January/2010 and March/2010, that are months of summer rains. The work involved the characterization of the study area and existing landslides, through bibliographic data collection; the application of visual analysis techniques for the extraction of landslide scars and fractures; preparation of maps for the landslide constraints and preparation of the susceptibility map. In the images from November only three landslide scars were extracted, while in January there were 166 and 111 in March. Difficulties were found with the shading in the images. From the relations among landslide scars, lithological units, relief systems, slope, downhill profile and the generated map of landslide susceptibility, presented in 1:70,000 scale, it was possible to conclude that slope is the main determinant of the process, allied secondarily to downhill profile, relief systems and lithology
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Construction of linear engineering as, roads, ducts and multiducts as roads, has a strong feature of the diversity of land on which they are deployed. This diversity involves properties geological, geomorphological and structural variety. The purpose of this work is to characterize the physical environment in relation to their ability to support the implementation of civil works linear. To achieve this, the use of orbital remote sensing, in this case, Landsat - TM. Interpretative techniques are applied to images in order to assess the forms of relief and drainage found that they can set properties and have built a favorable meaning or not to implement these works. The results and thematic maps presented in this study allow us to promote the geoenvironmental analysis for the planning phase sustainable linear civil constructions (roads and multiducts)
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Pós-graduação em Estudos Linguísticos - IBILCE
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The direct and indirect effects of atmospheric aerossols in the amazonic climate have been focus of many published. This work aims to analyze a possible relation among Burns, atmospheric aerossols and precipitation above South America. It uses the avaluable data from the satellites AQUA/TERRA and TRMM and the images furnished by NOAA and GOES. These analysis can provide some explanations about the effects of emission of aerosols by burns on the composition of atmosphere and cloud formation, mainly in Amazon. We use the Aerosol Optical Depth (AOD) from MODIS/TERRA-AQUA, burns index from CPTEC and rain rate from TRMM. The data we use were obtained from 2000 until 2012. The study is divided in two parts. In the first one, it was performed a quantitative analysis between number of burns and aerosols emission. It was identified a great variability in space and time of the AOD on South America. On the north, northeast and center-west, the AOD is significant during the winter period, with peak on August and September. The southeast is affected by aerosols from center-west due to the dynamical transport. In the second part, it was evaluated the relation between AOD and precipitation in a 13-year period. The statistical analysis shows up a negative correlation of 0.72 between August and October, on Legal Amazon. These result indicate an inverse relation between AOD and rain rate. The other months present not significant correlation. These results are in a good agreement with the literature, in which in-situ methods were applied or combined with satellites data. The increasing of aerosols concentration in the atmosphere are reinforced during drier years. It can affect the increasing process of water drops, decreasing the precipitation. We also verified higher values of AOD (0.25 - 0.3) during years with El Niño, than the climatologically average (~0.15 - 0.2), ... (Complete abstract click electronic access below)
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Pós-graduação em Agronomia - FEIS
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Pós-graduação em Agronomia - FEIS
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Pós-graduação em Engenharia Mecânica - FEG
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Pós-graduação em Engenharia Civil - FEIS
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Pós-graduação em Agronomia - FEIS
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Blooms of phytoplankton can be a risk to human health and aquatic biota, so the adoption of monitoring methods of phytoplankton and mechanisms for preventing its occurrence are needed. Thus, traditional monitoring methods could be more effective if complemented by approaches using the optical properties of phytoplankton pigments by means of Remote Sensing. In order to evaluate the potential of multi-scale remote sensing for detection of the phytoplankton activity, a study area was selected in Nova Avanhandava reservoir, located in the Tiete River, SP. For this analysis, hyperspectral field data and multispectral images of low and medium spatial resolution (Modis and RapidEye) were acquired and were related to indicator limnological variables of phytoplankton behavior; chlorophyll a and phycocyanin. The results show that a specific spectral band of RapidEye system (690-730 nm) allowed detect chlorophyll a and to evaluate the phytoplankton biomass, however hyperspectral data are needed to detect the phycocyanin pigment, indicative of cyanobacteria.
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In this letter, a semiautomatic method for road extraction in object space is proposed that combines a stereoscopic pair of low-resolution aerial images with a digital terrain model (DTM) structured as a triangulated irregular network (TIN). First, we formulate an objective function in the object space to allow the modeling of roads in 3-D. In this model, the TIN-based DTM allows the search for the optimal polyline to be restricted along a narrow band that is overlaid upon it. Finally, the optimal polyline for each road is obtained by optimizing the objective function using the dynamic programming optimization algorithm. A few seed points need to be supplied by an operator. To evaluate the performance of the proposed method, a set of experiments was designed using two stereoscopic pairs of low-resolution aerial images and a TIN-based DTM with an average resolution of 1 m. The experimental results showed that the proposed method worked properly, even when faced with anomalies along roads, such as obstructions caused by shadows and trees.
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Image segmentation is a process frequently used in several different areas including Cartography. Feature extraction is a very troublesome task, and successful results require more complex techniques and good quality data. The aims of this paper is to study Digital Image Processing techniques, with emphasis in Mathematical Morphology, to use Remote Sensing imagery, making image segmentation, using morphological operators, mainly the multi-scale morphological gradient operator. In the segmentation process, pre-processing operators of Mathematical Morphology were used, and the multi-scales gradient was implemented to create one of the images used as marker image. Orbital image of the Landsat satellite, sensor TM was used. The MATLAB software was used in the implementation of the routines. With the accomplishment of tests, the performance of the implemented operators was verified and carried through the analysis of the results. The extration of linear feature, using mathematical morphology techniques, can contribute in cartographic applications, as cartographic products updating. The comparison to the best result obtained was performed by means of the morphology with conventional techniques of features extraction. © Springer-Verlag 2004.
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Pós-graduação em Ciência Florestal - FCA
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Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)