National Institute for Space Research
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Discrepâncias obtidas entre o processamento e o ajustamento dos dados GPS nas extensões nativa e RINEX
No full textThe necessities of the contemporary world require agility and precision with respect to the geodetic positions. Spatial positioning technologies such as Global Navigation Satellite Systems have been applied in the fields that require reliable spatial information. Thus, there are many brands of receivers and GNSS data processing programs on the market. Considering this, it was verified the need for standardization of the data collected by GNSS receivers to be processed by any software. Therefore, the Receiver Independent Exchange Format (RINEX) was designed. This study aimed to investigate whether there are significant discrepancies in the estimation of horizontal and vertical components of the stations, with the use of files in raw and RINEX format. Accordingly, the screening of the local GNSS network stations of the Universidade Federal de Uberlandia was performed using single frequency (L1) Global Positioning System receivers (GPS), applying the relative positioning static method. Thereafter, the processing and the adjustment of GPS data were performed in raw and RINEX. The precision between the solutions achieved was analyzed under the proposed methodology as well as the discrepancies between the estimated coordinates of the stations in terms of their local coordinates. The results concluded that there arent significant differences in the use of these files. However, it is recommended to analyze a longer period of data, different stations in different screening conditions, and to use different applications for converting raw files to RINEX files, and processing software of GNSS data. Thereafter there will be more parameters to make more judicious analyzes.Pages: 5132-513
Abordagem bayesiana na epidemiologia espacial de notificações de casos de dengue no Estado de Goiás
No full textThematic maps are largely used in public health for the description and analysis of geographic variations of events, like diseases, aiming to detect high risk areas or spatial predominance. The present work is part of a number of studies of mapping of spatial epidemiology applying Bayesian methodology. In this case, as input was entered crude rates of incidence of dengue disease, which were corrected using Global Empirical and Local Empirical Bayesian estimators. We focus in Goiás State (Brazil) estimating regions where local people is submitted to epidemiologic risks. Dates were obtained from Sistema de Informação de Agravos de Notificações (SINAN-NET) in DATASUS for the years of 2009, 2010 and 2011. Spatial statistics calculations were run in the software of geographic system information (TerraView 4.2.0) to give cartographic representations that show the risk distribution obtained for each estimator: crude rates, Local Bayesian an Global Bayesian. The results show that the Bayesians estimators yield more accuracy in risks estimate for events recorded. These can minimize problems due null notifications (false positive) and avoid influence of population size. Therefore, this approach points clearly the most affected cities by the disease.Pages: 8554-856
Geotecnologias como Indicador de Riscos Ambientais em Faixas de Dutos de Combustíveis
No full textIt is estimated today in Brazil an invisible road network formed by more than 14,000 kilometers of oil pipelines, which connect all Brazilians regions. Based on this context, companies operating in this sector have a large environmental responsibility. The present study aims to present a qualitative methodology to indicate areas potentially susceptible to environmental risks. To the execution of methodology were used: map of soils, limits of pipelines range, contour lines, satellite imagery, climatological information and technical standards. From the determination of the variables: erosivity (R), erodibility (K), length of slopes (L), slope (S), use and management (C) and conservation practices (P) and the generation of six maps of susceptibility, it was possible to identify areas with environmental risks at three levels (low, moderate and high). The methodology is currently undergoing field validation of the results.Pages: 6791-679
Análise das técnicas de fusão de imagens aplicadas ao satélite CBERS-2B (CCD-HRC)
No full textThis work presents the results of the fusion process analysis from CBERS-2B (China-Brasil Earth Resources Satellite) orbital images applying the approaches HSV (Hue-Saturation_Value), Normalized Color, Gram-Schmidt and Principal Components. CBERS spatial resolution is 20 meters for multispectral image from CCD (Charge-Coupled Device) sensor and 2.7 meters for the panchromatic image from HRC (High Resolution Camera) sensor. With the fusion approaches was possible to evaluate the visual quality, transfer details and spectral fidelity. It can be observed that the images generated by the approach have satisfactory results in terms of visualization and definition of the objects that compose this one, making it possible verify the good definition of features such as vegetation, land use and road network. The results show that the four techniques analyzed showed gain in the quality due to improved spatial resolution, providing larger distinction of detail in the images. It can also be concluded that the approach based on principal components showed the best results in analysis of the detail transfer from original panchromatic to fused multispectral image. In the analysis of spectral fidelity, the best result for the band 1 was presented by Gram-Schmidt technique and for bands 2 and 3 the best results were achieved with the technique of principal components.Pages: 2188-219
Dinâmica do desmatamento na área de influência das usinas hidroelétricas do complexo do rio Madeira, RO
No full textThis paper presents an analysis of deforestation in Porto Velho municipality using Prodes data from 2001 to 2011, TerraClass land use data of 2008, and socio-economic data acquired from interviews with key informants in local Institutions during field work in 2012. The analysis was performed considering the period which Santo Antônio and Jirau dams started to be constructed, from 2008 to 2011, and the period before, from 2001 to 2008. An analysis with cells of 5 X 5 km was carried out allowing us to observe deforestation dynamic in Porto Velho and neighbor municipalities. Aiming at analyzing deforestation inside Porto Velho municipality the area was divided into 5 regions considering theirs dynamics and historical context. The causes of deforestation pointed out by local interviewers varied for each region considered and the factors associated to the construction of the dams affected each region in different intensity and manners. The analysis also showed that one of the most important factors influencing the deforestation dynamic in Porto Velho was the fact that this region is an agricultural frontier in expansion since the end of the 90s, presenting frequent problems related to land tenure, including invasion of public lands and protect areas. Aiming at controlling deforestation, the historical context must be considered before dams construction and an integrated plan must be elaborated and coordinated by federal government involving state and municipalities and their institutions.Pages: 7499-750
Mapeamento do uso e ocupação do solo utilizando imagens de satélite do sensor TM/Landsat 5 no litoral sul do Rio Grande do Sul, Brasil
No full textThe following paper aims at mapping the areas of use and occupation of soil in the south shore of Rio Grande do Sul using Geoprocessing and remote sensing/ detection. The area of this study is located between the cities of Rio Grande and Santa Vitória do Palmar. There were performed specific classification techniques of non-supervised orbital images from the sensor Landsat TM 5 using the tool SOM (Kohenens Self-Organizing Map) from the software Idrisi Selva\uae, making it possible to discuss the spectral answers of the targets and of the field observation.Pages: -920
Análise da estrutura de disseminação de dados espaciais do município de João Pessoa-PB pela prefeitura através da internet
No full textThe use of spatial data for planning and land management have become increasingly common in Brazil. Faced with the need to resolve land conflicts urban the Brazilian cities, especially the capital, developed in recent decades cadastral systems based on technology Geographic Information Systems (GIS). With the popularization of geoinformation technologies, various productive sectors also began to use spatial databases as a subsidy for the development of their activities. The demand grew, in view of the possibility of obtaining data free of charge in the case of private enterprise, and partner in the case of other public institutes of the same or different administrative levels. However, currently there is still difficulty that is faced by different sectors of society to obtain the desired product or data. Frequent visits, queues, accumulations of application processes, overloading of professional care, many of the problems encountered. The Board of Technical Registration and GIS, the City of João Pessoa, chose to make their products over the Internet in an attempt to minimize the direct search by industry data thus relieving the flow of processes, allowing the attendance of other demands that are also part of everyday life in the industry. This article aims to analyze the structure of dissemination of spatial data from Joao Pessoa in an objective manner and, where possible, contribute to improving the system already deployed, contributing to greater satisfaction of the population.Pages: 4837-484
Comparing different textural approaches to extract human settlement from CBERS-2B data
No full textAlthough it is well-known that textural features have proved to be the most relevant ones to extract human settlements from high spatial resolution (HR) panchromatic remote sensing images, it is still to be investigated in details which is the most efficient one. This is especially true when looing for a methodology aiming at settlement extent detection and at the same time able to cope with various and different definitions of what a human settlement is. In this paper we compare two approaches developed for this task and already checked at the global level on HR and VHR SAR data, comparing their performances on two complete CBERS-2B panchromatic scenes. The processing chains, their results and the computational loads of two approaches, one based on the co-occurrence contrast feature and one on the occurrence range feature, are introduced, evaluated, and discussed. The relevant outcome of this research is that there is no clear winner, and less complex/less efficient approaches may still be able to provide suitable results. Detection accuracy and false positives (commission errors) varies according to the geographical scale considered and the features used to identify the settlement, such as their size, number of built-up stricture, built-up area density and so on.Pages: 2193-220
Series temporales de áreas quemadas en regiones semiáridas (2001-2011). Validación de productos globales existentes y propuesta metodológica
No full textThe study of spatio-temporal variation of burned areas patterns at regional scale provides an overview of the dynamics of ecosystem processes and vegetation patterns. Several global fire related products are currently freely available. In this work we evaluated MOD14, MOD45 and L3JRC products. It has been pointed out by several authors that those products have shortcomings such as efficiency variation depending on ecosystem features or differences in evaluating extent and location of affected areas. The aims of this study were: 1) to test the accuracy of the above mentioned products to detect burned areas in a semiarid region and, 2) to generate a new method to detect fire affected areas, using Northern Patagonia (Argentina) as study case. We developed an algorithm based on regional growing segmentation technique on NBR and dNBR indexes using MODIS (2001-2011) time-series. Validation of global products with reference maps showed poor agreement, on the contrary, our algorithm performed better. Results in area estimation were quite different; MOD45 estimated 31,460 km², MOD14 21,656 km² and L3JRC 108,867 km² whereas our algorithm estimated 42.860 km². These results highlights the need for caution when applying global burned products in a local or regional scale.Pages: 6308-631
Diagnóstico das Áreas de Preservação Permanente na sub-bacia do córrego Lageado, localizado na Área de Proteção Ambiental do rio Uberaba, Uberaba-MG
No full textThis study aimed to diagnose the use and occupancy of permanent preservation areas (APP) in the watershed of the stream Lageado localized in Uberaba (MG), based on digital images of the satellite ResourceSat-1, Datum WGS84, Zone 23 and the corresponding date 05/04/2012. To develop this work were mapped areas of permanent preservation with the use of a classifier digital supervised and identified instances of conflict of use, with reference to cool the Brazilian Forest Code (Law no. 4771/1965), Law 14309/2002 (forestry policy and protection of biodiversity in the state of Minas Gerais) and resolution no. 303/02, CONAMA. This article analyzed through quantitative parameters and with the use of Geographic Information Systems to maintain permanent preservation areas, as recommended by the legislation widths along the water bodies. The results showed a deficit of preserved areas along the riverbanks of approximately 2,17 Km ², that are not in accordance with the law. The area occupied by the Agriculture improperly is 0,8257 Km ², livestock Km ² 1,3082, 0,0151 km ² urbanization, mining 0,0216 km ² and exposed soil within the APP 0,0117 km ². Thus, predominates in the Watershed study in the occupation of Permanent Preservation Areas for grazing areas.Pages: 7329-733