National Institute for Space Research
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Uma nova abordagem para extração de feições arquitetônicas através de dados provenientes do laser scanner terrestres
No full textTerrestrial laser scanner systems are an important device for data acquisition of three-dimensional objects. In recent years, technological advances have allowed these systems to acquire data with greater speed and accuracy. The high density of points, cloud of points acquired by this equipment has encouraged research into new methodological approaches to extract the information contained in those datasets. Data extraction issue is still theme of study, researchers have been carried out their work using only the geometric information (X, Y, Z) contained in the data. This article describes a new approach for extracting the information contained in these data: the intensity value. Thus the main objective of this work is the extraction of architectural features of buildings from terrestrial laser scanner data through classification and segmentation algorithm that is the case with the k-means algorithm. The architectural monument scanned in this work was the Palacio Giuseppe Garibaldi located in Curitiba Paraná, this building, listed as cultural and historical interest. The results indicate that the use of the value of the data contained in the laser intensity can greatly support the procedures of extracting the architectural features of building and its reconstruction.Pages: 1959-196
Correção geométrica da máscara de áreas alagáveis da bacia amazônica
No full textWetlands are important sources of carbon emissions. Accurate mapping of these environments is essential to produce precise estimates of this greenhouse gas. Since mid-2000 a map of wetlands for the entire Amazon basin is available. This map, called wetlands mask, has been used in some regional studies. However, geometric distortions have prevented its use for local-scale studies, where precise positioning is required. In this paper, we present the methodology to reduce these geometric distortions using SRTM-DEM as reference. To achieve this goal, a computer program was developed. In order to rectify local distortions, the wetlands mask was vectorized and overlaid on SRTM-DEM. From a control point set collected in both mask and SRTM-DEM, the whole area was decomposed into small triangles. A mathematical transformation was determined using the vertices of each pair of triangles (correct and warped) and was applied over all polygons enclosed by the triangles. The geometric correction of the distortions caused no significant changes in the estimate of the total flooded area. Furthermore, the displacements needed for correction rarely exceeded 1 km. The geometric correction substantially improved the consistency between the wetlands mask and the SRTM-DEM data.Pages: 5507-551
Dados de sensoriamento remoto de alta resolução para estudos de biodiversidade: Identificação de copas de palmeiras (Arecaceae) em Ubatuba, São Paulo
No full textThe Atlantic rain forest has the largest continuous areas of forest remnant in the state of São Paulo, where palm trees are an important component of its biodiversity. The typical architecture of their crowns makes them easily to distinguish from other trees in the forest canopy by remote sensing. This study aimed to evaluate the potential of high resolution images for identification of palm trees in the region of Ubatuba, in the north coast of Sao Paulo state. A QuickBird image (0.6 m spatial resolution) referred to 2007 was first used to identify palm species by visual interpretation, that was checked by the fieldwork in 2012. From 50 points of palms identification, 23 corresponded to specimens identified correctly: Elaeis guineensis (oil palm), Bactris gasipaes (peach palm), Roystonea oleracea (imperial) and Attalea dubia (indaiá). Individuals of açai, juçara, hybrids of juraça with açai, Euterpe oleracea (açai), Archontophoenix sp. (royal Australian), Syagrus romanzoffiana (gerivá) and Cocos nucifera (coconut) were recognized only in the field and then located in the image. The second approach tested image segmentation with different thresholds of similarity and area, and the application of image contrast enhancement for areas with different contexts where palm trees were identified. Morphological characters and data segmentation off palm trees were summarized to facilitate the recognition of the crowns at QuickBird similar image. Our results indicated the palm species visually identifiable and evaluated the digital procedure to detect and map canopy palm trees at high resolution remote sensing image.Pages: 1410-141
Evaluation of digital elevation models (DEMs) from high and low pulse density in LiDAR data
No full textIn this paper we evaluated and compared digital elevation models (DEMs) and tree height estimation from high and low pulse density LiDAR data. To compare DTMs were calculated root mean squared error (RMSE), coefficient of variance of the root-mean-square error (CV-RMSE) and mean absolute error (MAE). To tree height estimation was inventoried four hexagonal plots, each approximately 1 ha in size. Within the plots were stem-mapped and measured individual tree height. Based on our results, we conclude that low pulse density LiDAR can be applying to terrain model create, however, recommended just to DTM created. Furthermore, when desire biometrics tree estimation from LiDAR, we recommended that use high pulse density, because this is more accuracy.Pages: 6065-607
Qualidade de metadados geoespaciais confome a ET-PCDG
No full textThe presidencial degree number 6.666, from november 27 of 2008 estabilish the Infraestrutura Nacional de Dados Espaciais do Brasil (INDE). Acording to this degree, INDE is an integrated set of technologies, policies, coordination and standards necessary to promote the generation, storage, access and dissemination of geospatial data produced by public agencies of executive power. One of the responsibilities was the creation of the Action Plan for Implementation of INDE (CONCAR, 2010), a document that defines the activities, goals, and responsible for the implementation of an SDI in Brazil. In this document is designed the Brazilian Army with assignment of preparing the Technical Specification for Geospatial Products Data Sets (ET-PCDG), which, in addition to setting standards for products to become of official use in INDE, defines the group metadata for each type of product provided. It has also been appointed to the Brazilian Army the assignment of preparing the Technical Specification for Quality Control of Geospatial Product Data Set (ET-CQPCDG), which defines the procedures for the evaluation of the quality of cartographic products and their metadata. The objective of this work is the evaluation of 49 metadata for the vector 1:250,000 sheets of southern Brazil contained in BDGEx in accordance with ISO 19115:2003, the profile MGB, and ET-PCDG. The results where that the metadata evaluated had only errors that do not compromise the quality, verifying that the metadata contained in BDGEx are of a high reliability.Pages: 2463-247
Geoprocessamento como ferramenta de planejamento e gestão no Vale do Sereno em Nova Lima, Minas Gerais
No full textThe region of Vale do Sereno, located in the municipality of Nova Lima, has been the scene of considerable conflicts in terms of different land use interest. The housing market has been gaining space in the region in conflict to environmentalist issues, since it is a place endowed with significant vegetation and water resources. These reasons, coupled with the permissiveness of the zoning of the municipality, have been the main causes for the suffered strong real estate pressure in the region. The objective of our work is to diagnose the key issues faced by the region and create mechanisms for planning and management that can be used as a model not only for the city hall of Nova Lima, but also for the companies responsible for the implementation of large projects in Vale do Sereno. In order to enable such analysis, field work with experts in the areas of geology and city planning, interviews with local people and the use of GIS tools were necessary. The results obtained by this work were the creation and manipulation of data that enabled the mapping of critical points, conflicts and their vocations. Therefore, by establishing accurate diagnoses as this and by readjusting of zoning, it will be possible to explore the potential of the region in a more sustainable way.Pages: 3833-384
Emprego de técnicas de realce em imagens Landsat/ETM+ para o detalhamento geológico da borda Leste da Bacia do Parnaíba
No full textThe Geological Survey of Brazil-CPRM has studied the groundwater at the Eastern border of Parnaíba Sedimentary Basin, with the goal to increase water availability for cities at the plateau of the Serra Grande Aquifer, along the border between Ceará and Piauí States, Northeast Brazil. Images from Landsat 7 ETM + sensor were processed with the combination of two techniques that enhances multispectral information and proves suitable to highlight geological and structural features at Crateús/Ceará and Buriti dos Montes/Piauí regions. The RGB composite originated by the band ratio of the principal components PC4/PC5 (R-Red), PC2/PC1 (G-green) and PC3/PC4 (B-blue) distinguished the medium-to-fine grained sandstones of Tianguá Formation, the coarse-grained sandstones of Jaicós Formation and enhanced the Itaim Formation (base of Canindé Group), with fine-grained sandstones interbedded with shales. The color composite RGB 457 supports this discrimination, besides enhances the arboreal vegetation from open shrubby at the top of the plateau border. The combined PDI techniques allow the improvement of geological map and the mapping of geologic units which were not distinguishable on semi-detail scale before. Structural lineaments were interpreted after the fusion of the Landsat products with SRTM elevation data. The generation of slope orientation and gradient maps were integrated with the structural information to help understand localized groundwater flow to the east, contrary to westerly regional flow.Pages: 3664-367
Caracterização pedológica e uso das terras na Área de Proteção de Manancial do Córrego Quinze, DF
No full textThe Protection Area of Water Sources of Quinze Stream (PAWS), with an area of about 4,000 ha, is mainly composed by the Pequizeiros Ecological Park and Santos Dumont Rural Center, a region of great importance to agriculture in the Federal District. This study aimed to characterize the soils and check the land use and occupation of the PAWS of Quinze Stream to check the sustainability of this use in this protection area of Distrito Federal. Was implemented a digital database using ArcGIS 10 software, with maps of soils, agricultural capability of the land, geomorphology and geology available of the study area. Was conducted the study of relations between classes of soils, geomorpholgy and parent materials, using ArcGIS 10. Were selected soil profiles representing the pedomorphogeological relationships established, representing the soils distribution in the landscape of the PAWS of Quinze Stream. Was generated land use and occupation map of the PAWS of Quinze stream through the automatic classification of Landsat image using the software ENVI 4.4, and established classes of land use and occupation. Was evaluated the adequacy of the agricultural capability through the land use and occupation map generated of the study area. The results show Oxisols occur in areas of lower slopes in flat relief and Histosols and Plinthosols at areas of greatest slope near the bed of the Quinze stream. The land use and occupation of the PAWS of Quinze Stream was considered appropriate in relation to agricultural suitability.Pages: 340-34
Programação paralela com GPU aplicada ao registro automático de imagens de satélites
No full textThis paper describes the use of general-purpose programming on graphic processing units (GPGPU) to improve the performance of automatic image registration methods based on the normalized cross correlation index. These methods use the correlation index to select control points that are later used to register the image. First we present how the performance is seriously degraded when the translation error between the reference and work image is in the order of some kilometers, as it has been the case for CBERS satellites. A parallel algorithm is proposed to improve the performance, the results indicate a speed-up of almost 30 when compared to the sequential method, using off-the-shelf GPU hardware. We conclude proposing other applications of the same technology to improve the geometric quality assessment procedures.Pages: 5978-598
Monitoramento dos impactos do Complexo Petroquímico do Rio de Janeiro utilizando dados Landsat
No full textRio de Janeiro Petrochemical Complex (COMPERJ) is scheduled to begin operation in 2014. The facility is located on a 45 square kilometers land in Itaborai, Rio de Janeiro. It is expected that COMPERJ construction increase the pressure on local infrastructure conditions and the environmental system. Accordingly, this manuscript aims to analyze the impact of COMPERJ based on remotely sensed data from TM and ETM+ sensors on board Landsat-5 and 7 satellites, respectively. The remote sensing data were used in the retrieval of land-surface temperature (LST), the normalized difference vegetation index (NDVI) and the based built-up index (IBI) for a period of 8 years allowing the temporal evolution observation of these parameters before and after COMPERJ construction. The temporal evolution of the TSC, NDVI and IBI was verified by the Studentss t statistical test conducted at the 5% level. Post-construction results show a ring of LST concentric values coming from the colder outer part toward the warmer core. From the outside to the core, the temperature gradient is close to 8.0 C with spatial characteristics similar to an urban heat island. LST presents a huge variability associated with weather and climate conditions and therefore it was not possible confirm based on the Students test that LST values were increased after COMPERJ construction. On the other hand obtained results confirm, within the significance level assumed, that NDVI (IBI) has decreased (increased) just inside the construction area of COMPERJ.Pages: 975-98