National Institute for Space Research
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Geração de modelos digitais de elevação com base em técnicas de estereoscopia digital, por meio de imagens VANT: Subsídio a identificação de manchas de desmatamento em áreas de preservação permanente
No full textNowadays the georeferenced management of rural zones has becoming increasingly present in Brazil, by the utilization of orbital images or orthophotos acquired by manned airplanes, however, the acquisition methods of such products are expensive, which makes it inaccessible to small farmers. Given this, its necessary to consider the adoption of cheaper orthophotos collected by unmanned air vehicles, so called UAVs. Aiming to discuss the application of such data, the principal goal of this study was to present a methodology for semi-automatic generation of digital elevation models (DEMs) and orthomosaics using photos acquired by non-metric cameras in the visible range of electromagnetic spectrum, onboard an ultra-light UAV. Using the derivate data, it was identified deforested areas located on environmental preservation zones surrounding the rivers. The study site is located near the city of Figuerião which is located on the state of Mato Grosso do Sul/Brazil. Through the adopted methodology it was possible to generate a DEM and an orthophoto with an spatial resolution of 0.6 and 0.2 m, respectively. The results have showed that the generated data was helpful to aid the management of small farms, especially, regarding the mitigation of environmental problems, nevertheless, its still necessary increase the application of UAVs in photogrammetric missions which will make possible the improvement of methods and techniques to process data derivate from photographs taken by UAVs. Key Words: Photogrammetry; UAV; environmental preservation zones, fogrametria, VANT, áreas de preservação permanente.Pages: 2113-211
Comparação da cobertura vegetal entre fragmentos de floresta estacional semidecidual por Modelo Linear de Mistura Espectral
No full textBotanic gardens are essential for plant and environmental conservation, also for leisure and education, mainly for communities living nearby. The Botanic Garden of Botucatu Biosciences Institute (JB/IBB) develops research and education projects and that´s why its preservation and the preservation of its forest fragments are very important. Nowadays, remote sensing is an indispensable technique for environmental evaluation and environmental monitoring, and one of its uses is the study of forest canopy. This work aimed a temporal analysis of the forest fragments canopy on JB/IBB. The study compared semidry tropical forest fragments from JB/IBB with a very preserved control fragment of semidry tropical forest on the Edgardia farm, also in Botucatu, SP. Landsat 5 TM sensor images from 1985, 1992, 1999, 2005 and 2011 were use, and the software SPRING was used for image processing. The evaluation was made by the application of Linear Spectral Mixture Model LSMM). After applying the Linear Spectral Mixture Model, polygons were drawn upon the areas of study and the mean values of vegetation for each image were calculated. The t-Test was used to compare the mean values. The test shows no difference for both JB/IBB and Edgardia (t=0.1003, p=0.9227). It possibly means that the ecosystem processes are working well on the fragments of JB/IBB as they are on Edgardia forest. So, the managers of JB/IBB ought to work for ensure the ecosystem process and the long-term conservation of the fragments.Pages: 3133-313
Indicação de possíveis áreas impactadas em acidentes ambientais por meio de processamento digital de imagens multiespectrais Landsat
No full textThe delimitation of an impacted area by environmental accident is not an instantaneous work. Its calculation by the short term effects is considered undersized by neglecting long term effects that can be manifested long after the accident. This study shows impacts on vegetation after two huge environmental accidents occurred in distinct areas measured by difference in NDVI signals after and before the events. The NDVI signals were calculated through Landsat 5 and Landsat 7 images. One of the areas, where the pollutants had the natural drainage channels as unique way of dispersion, the effects in the water bodies banks were very pronunciated, expressed by abrupt changes in NDVI values. The second area, where the fate of the pollutants should be associated with the estuarine dynamics, mangrove fringes areas have shown slight changes in NDVI values, decreasing its values soon after the accident and recovering its original values five months after. This study shows that impacted areas can be proposed after an environmental accident by changes in NDVI values, with its long term effects continuing to be monitored, when multispectral images are available. All proposed areas must be confirmed by field examinations. This study indicates applications where the dynamic of pollutants dispersion is not obvious, as well in monitoring the recovery process of impacted areas.Pages: 1464-147
Inferência sobre o conforto domiciliar rural do município de Viçosa-MG utilizando análises multicritério
No full textThe Statute of the Cities, states that municipalities should perform diagnostics with the aim of locating social, environmental and economic problems that are occurring in both urban and rural. For this purpose are used policy instruments in which the Master Plan of the city stands, it must be updated every 10 years in order to guide the managers and the management of urban and rural spaces, ensuring a good quality of life to population. For this work was chosen Viçosa, which is located in the Zona da Mata - MG, the city has a history of occupation preceding the rural urbanization. It is necessary to assess whether the residents of the rural area are also being assisted by the administration public. The factors analyzed deal mainly supply of essential public services such as access to water, electricity and sewage services garbage collection and others that affect their livelihood as distance from access roads and distance from hydrography, these factors contribute to the construction of the concept of home comfort. Therefore, this study aims to develop a map of comfort at home in order to assist the government in establishing actions that will improve policies and management planning of the town. The methodology applied in the study involves the use of techniques of geographic information system through multicriteria analysis. The results showed that the more distant urban areas, the provision of public services is more precarious pointing to a smaller home comfort in these regions.Pages: 3744-375
Desenvolvimento de um banco de dados geográficos para a categoria de informação hidrografia da ET-EDGV em um Sistema Gerenciador de Banco de Dados
No full textThis paper describes the implementation of the hidrography category information the conceptual model, about the Technical Specification for the Structuring of Data Vectorial Geospatial (ET-EDGV), in a spatial relational database management system. The physical modelling of the spatial-temporal database was developed with the Sybase PowerDesigner CASE tool. The spatial-temporal database implementation was done using Structured Query Language. The contribution of this work is the spatial-temporal database implementation, hidrography category information from ET-EDGV version 2.1.3, for the spatial relational database management system PostgreSQL version 9.1 and PostGIS 2.0. It was concluded that ET-EDGV adoption enables the geographical data standardization and normalization stores in the spatial relational database management system.Pages: 2471-247
Sensoriamento remoto hiperespectral aplicado à detecção de estresse em plantas causado pela contaminação do solo com hidrocarbonetos líquidos
No full textThis paper explores hyperspectral remote sensing data and techniques for the detection of stressed plants contaminated by diesel and gasoline. A field experiment in real scale was conducted in which Brachiaria brizantha pasture plants were grown over soils contaminated with small volumes (2-12.7 L) of liquid hydrocarbons (HCs). Canopy reflectance spectra of contaminated and control plants were acquired within 350-2500 nm wavelengths using an ASD FieldSpec\uae Hi-Res spectroradiometer in nine dates. Also, a hyperspectral image of the experimental area was acquired with the ProSpecTIR-VS airborne sensor during the experiment. Reflectance spectra were mathematically transformed by means of first derivative (1D) and continuum removal (CR) techniques. Exploratory data analyses were conducted using principal component analysis (PCA), which showed that CR improved the extraction of information from the dataset. Two spectral indices computed from CR data were explored: the Band Depth Ratio (BDR) and a new index, the Plant Stress Detection Index (PSDI). Based on the ultraspectral data acquired with the FieldSpec, it can be stated that if the BDR = 1 at approximately 1720 nm the spectrum refers to a plant contaminated with HCs. Also, if the PSDI has a negative value between 560-600 nm in FieldSpec data and between 575-601 nm in ProSpecTIR-VS data it can be inferred that the spectrum refers to a stressed plant. Based on our results, it is concluded that the BDR and the IDEP indices represent an objective analysis to identify canopy spectra of stressed brachiaria plants contaminated by diesel and gasoline.Pages: 8908-891
Explorando a extensão WKT Raster do PostGIS para armazenamento e manipulação de imagens de sensoriamento remoto
No full textSpatial extensions allow DMBS systems to story and query spatial data using high-level query languages capable of expressing complex queries mixing descriptive and spatial criteria. This works explores the WKT Raster, part of PostGIS, the spatial extension for PostgreSQL, to manage raster data, more specifically remote sensing imagery. This spatial extension was chosen, because it is, to the authors knowledge, the most mature product that is free of license. Some typical remote sensing operations are executed using only the query language available in the WKT Raster. The results show that WKT Raster is a promising tool to handle raster data in object-relational databases. Some interesting features are the integration to the spatial types used to handle vector data and the large number of processing operators.Pages: 4700-470
Aspectos geomorfológicos da bacia hidrográfica do rio Jaibaras - CE
No full textThe relief is an important determinant of the use and occupation of space, where the man lives in support of natural and social interactions. The river basin Jaibaras located in the north central portion of the State of Ceará, bathing nine counties, is an important subbacia the river basin Acarau. For the analysis of natural resources was considered a watershed as the territorial unit for the development of the study, basing themselves on the basis of theoretical and methodological in general systems theory and analysis geosistêmica were evaluated in their processes of evolution. Using techniques of remote sensing and GIS was taken into consideration the territorial dynamics. With the analysis of landscape were established five categories of media morphodynamic, and considering the vegetation cover of the landscape as a stabilizing factor, thus enabling to determine the degree of vulnerability of each subsystem. The river basin has a Jaibaras landscape diversity that directly reflect the conditions governing their use and occupation, these differences were compartmentalized into four environmental systems, Deposits Quarternários, Depression Country, Solid Waste and Plateau Sedimentary Ibiapaba, and these systems were subdivided into ten subsystems, each with its natural characteristics that possess a certain degree of homogeneity physiognomic, and subject to the conditions of use and occupation, setting the main environmental impacts in the basin.Pages: 3542-354
Análise da separabilidade de materiais urbanos utilizando imagens das bandas VNIR, SWIR e TIR do sensor HSS
No full textUsing a combined approach of the airborne HSS (Hyperspectral Scanner System) images from the visible/near-infrared (VNIR), shortwave infrared (SWIR) and thermal infrared (TIR) bands, the separability of specific urban materials, based on their spectral reflectance and emissivity, was analyzed. The HSS images were converted from radiance into surface reflectance using a MODTRAN4-based approach. The NOR (Emissivity Normalization) method was applied to the TIR images to determine the spectral emissivity. Surface reflectance and emissivity spectra of eight materials (concrete, fiber cement, red tile roof, asphalt, steel, soil, wood vegetation and grasslands) were analyzed qualitatively and quantitatively through principal component analysis (PCA). Results showed that some materials (e.g., asphalt and fiber cement) that did not present spectral features in the reflected region, displayed spectral features in the emitted spectral interval. The first component (PC1) was useful to differentiate the urban materials based on the average surface reflectance and emissivity, whereas the PC2 discriminated those of them with strong changes in the slope of the reflectance or emissivity curves.Pages: 1495-150
Produção geoinformacional e geovisualização para apoio a planejamento e projeto: um empreendimento piloto em realidade virtual
No full textBoth planning and projects need data and geographic information to meet the important demands of representativeness and accuracy. Regarding the representation, the arrangement of natural and cultural objects existing on the site is important to identify interference and environmental constraints to the construction and implementation of the project, in a clear way. As for accuracy, its importance is related to the growing demand for environmental interventions increasingly accurate. Several factors contribute to an increase in the demands of accuracy and representativeness. In general, all are associated with the technological development of the last two decades, when it expanded the possibilities of geoinformation production of higher quality. Thus, this paper presents the research and developments in geovisualization on virtual reality VR that have been undertaken to better understand and describe the role that this form of geovisualization may have in the future, in daily planning and projects. To develop this geovisualization pilot in RV were performed aerial surveys and various solutions have been implemented, in terms of the presentation of these data in a virtual reality room. Multidisciplinary meetings were performed to analyze the work environment created, in order to enable experiments increasing immersion and interaction with geoinformation. The experimental results of the first uses of this environment are reported and analyzed here, allowing for the first conclusions and the prospects for medium and long term arising from this pilot project.Pages: 4981-498