National Institute for Space Research
Biblioteca Digital da Memória Científica do INPENot a member yet
6175 research outputs found
Sort by
Imagens de alta resolução do satélite CBERS-2B/HRC e do Google Earth aplicadas na caracterização urbana de Alfenas-MG
No full textBrazilian population exceed 190 million people of which 84% live in urban areas. This configuration combined with the lack of public policies and effective urban planning reproduce numerous problems in most Brazilian cities, as inadequate infrastructure, pollution, deficient public transport, scarcity habitation, health and educations services collapsed, among others. The knowledge about the dynamics of urban areas and its configuration pattern is an important way to support alternatives aimed to minimize the urban problems. Nowadays remote sensing data and techniques have been an important instrument to describe the urban areas, especially remote sensing images with high spatial resolution. The main goal is to characterize the urban area of AlfenasMG from mapping the type of cover (roofs) present on the constructions to verify the residence distribution considering the pattern (high, median and low) of construction, industry and empty areas. Materials included images from CBERS-2B (CCD and HRC sensors), aerial photography and Google Earth images. In other to improve the visual interpretation of HRC images, IHS transformation was performed using CCD and HRC images. The mapping procedure was performed based on visual interpretation and considering five classes: ceramic roofs, fiber-cement roofs, metal roofs, mixed areas and empty areas. The remote sensing data allowed to separate the different types of roofs and also revealed the social and economic conditions of the population, exemplified by the presence of pools. Ceramic roofs are present in areas of better social and economic conditions, different of fiber-cement roofs that are present in peripheral areas. Metal roofs are verified in industrial areas.Pages: 2172-217
Análise comparativa entre dados de precipitação e de níveis de água estimados via produto MERGE e satélite ENVISAT na bacia Amazônica
No full textThe aim of this research was to compare MERGE rainfall and ENVISAT altimetry data in the Amazon River for. MERGE rainfall data is a new technique to combine TRMM (Tropical Rainfall Measuring Mission) satellite precipitation estimates with surface observations (Surface Synoptic Observations-SYNOP data) over the South American continent. The combination of data estimated by TRMM and the precipitation of surface are interpolated to a regular grid interpolation method using as the objective analysis of Barnes. The measures and estimates were compared at the virtual stations along the river. The satellite radar altimetry denotes good results of the water level for the period 2002-2010. The surface water level is measured within a terrestrial reference frame with a repeatability from 35 day. Using a 3D method (VALS Tool) for define the virtual station, were computed and analyzed time series of water stage together with the rainfall climatology series of MERGE rainfall data. The results show variations of the difference between the maximum and minimum rainfall, and water level, stations upstream has a gap lower than the stations located further downstream the river.Pages: 5721-572
Satellite Altimetry for Hydrology-A review
No full textWater is a critical natural resource upon which all social and economic activities and ecosystem functions depend. However, regular gauging networks fail to provide the information needed for spatial coverage and timely delivery. Although the space missions discussed here were not primarily dedicated to hydrology, 20 years of satellite altimetry have furnished complementary data that can be used to create hydrological products for river basin, such as time series of stages spread throughout the basins, estimated discharges of rivers, derive longitudinal altitude profiles of river bed, lowest and highest stages, or leveling of in situ stations. Raw data still suffer uncertainties of several decimeters. These require specific reprocessing such as waveform retracking or geophysical correction editing; much work still remains to be done. Inundated surfaces, and the time variations of their extent, are currently almost routinely computed using satellite imagery. Today, the altimetry techniques are evolving rapidly. One direction is the change of the radar band, from Ku to Ka. Other change is the replacement of today LR Mode to SAR or Interferometry modes. Both evolutions tend to diminish dramatically the ground footprint, reducing as much the contamination of the echo by the environment of the water body, and improving as much the vertical accuracy. Last, from 2015, the research class missions will be replaced by operational ones, making the long living of the sampling locations more certain. All the aforementioned technical evolutions will be grouped in the SWOT mission, a Ka band interferometric swath altimeter, the first satellite mission actually dedicated to provide full coverage of the continental waters, to be launched in the early 2020s. Besides its intrinsic improvement in the high resolution of height, slope and width of the reaches, SWOT will be an invaluable tool to put altogether in an inter-calibrated dataset all the nadir missions part of the aforementioned constellation.Pages: 5665-567
Análise da mudança da cobertura da terra na região do Parque Estadual do Araguaia, MT, por meio de classificação orientada a objeto e dados Landsat 5 TM
No full textConservation units (CU) are one of the best strategies to protect the natural heritage and ecological processes that govern ecosystems. Knowledge on land cover and land use is thus essential in these regions. Using object oriented classification, is possible to explore different spectral, textural and geometric attributes of land targets, represent a process similar to human cognition through the hierarchical and semantic relations of the different classes of land use. This study produced two maps of land use and land cover for the Araguaia State Park and its surroundings, for the years of September 2001 and 2011 before and ten after the creation of this conservation unit, respectively. These maps were produced using geographic object based image analysis (GEOBIA), and satellite imagery from Landsat-5 Thematic Mapper (TM). The accuracy of the object-oriented classification reached a kappa index of 0,77, and overall accuracy of 80,6%. The maps generated show that the zone surrounding Araguaia State Park has been suffering an ongoing process of degradation and Wooded Savannas are the vegetation types most impacted by this process.Pages: 7192-719
Variação espaço-temporal de NDVI em remanescentes de fitofisionomias da Mata Atlântica na Bacia Hidrográfica do Rio dos Sinos - RS
No full textThe application of NDVI (Normalized Difference Vegetation Index) in forests enables the analysis of their seasonal behavior, the diagnosis of spatiotemporal changes and phenological monitoring. This study aims to analyze the spatial-temporal variation of NDVI in remaining areas of vegetation types that comprise the Atlantic Forest in river basin of the Sinos, RS, Brasil. For this we used a time series of 205 images dates of the MODIS NDVI, where through the TSA tool, generated a set of three Principal Components (CP1, CP2, CP3) for winter and for summer. After we analyzed the average values of pixels of three samples for each vegetation type that comprise the Atlantic Forest: Forest of Semideciduous Lowland, Lower Montane Semideciduous Forest, Forest Semideciduous Montana, Araucaria Forest and Steppe, totaling 15 samples for each CP per season. It is noteworthy that the brightness values related to CP1 winter and summer are different, which shows the seasonal pattern of vegetation, especially in Semideciduous Forest. It should be noted also that the CP3 were those that showed better discrimination between classes of vegetation types, from the difference in brightness values between samples. Therefore, it was concluded that the analysis of time series by CP, compared with the individual images of NDVI, become more efficient in discriminating the classes of vegetation types as well, evidenced most clearly the seasonal behavior of the Atlantic Forest.Pages: 3176-318
"Cloud Detection Tool'' - Uma ferramenta para a detecção de nuvens e sombras em imagens de satélite
No full textThe DETER (Real Time Deforestation Detection) and SISPRODES (Annual Deforestation Monitoring) systems use satellite images for deforestation monitoring in the Legal Amazon. While DETER provides information about forest clearing in near real-time using low-resolution images (250 m), SISPRODES estimates the deforestation on a year-to-year basis using medium-resolution images(20-30 m). In both systems, clouds and shadows present in the images make difficulty the image analysis procedures. Within this context, this paper presents a methodology to detect clouds and shadow to assist PRODES and DETER systems to process the images. The method proposed in this work is based mainly on the image spectral information, and image processing techniques such as morphological filtering and threshold operations. Some experimental tests to valid the methodology are performed and although some confusion in detecting shadows still occurs the results are very promising.Pages: 4234-424
Geotecnologias aplicadas ao mapeamento da legislação ambiental na Área de Proteção Ambiental Municipal das Nascentes do rio Apa, Ponta Porã - MS
No full textThe objective of this study was to evaluate the current situation of the land use and vegetation cover, with the implementation of the new Forest Code (Law no. 12,651, 25 may 2012), to determine areas of environmental preservation and propose improvements that contribute to the maintenance of environment quality. The area chosen for the proposition and the Municipal Environmental Protection Area of springs of the Apa, created by Municipal Decree no. 4743/2004, with an area of 17.196,1589 is there, in the northwestern part of the municipality of Ponta Porã, State of Mato Grosso do Sul. Methods included the delimitation of the drainage network, definition of three slope classes comprising of 0 to 25\ub0, from 25 to 45\ub0 and greater than 45°, and the establishment of a "key of interpretation" to assist in the display of elements and their properties contained in orbital image, evaluation of land use and vegetation cover of the year of 2011 and implementation of the tracks of protection established by Law no. 12,651, may 25, 2012. It was observed that the APA the sources of the river Apa must have an area of APP of 732.38 ha, of this total only 590.57 there are preserved with forest fragments and 141.42 need to be recomposed. To solve this, it is must adopt technical procedures for the recovery of degraded areas, in order to maintain the proposed by category of Unit of conservation for Sustainable Use.Pages: 4185-419
Utilização do geoprocessamento no licenciamento ambiental, para mapeamento, quantificação e monitoramento de manguezais
No full textMangroves have a important role in maintenance of environmental quality on coastal areas. Human activities has been responsible for extensive damages to these biomes despite its importance. Researchers estimate the area losses around 1% a 2% each year. This rate of losses shows the urgency of creation of public policies to preserve this biome. The remote sensing and geoprocessing has been turning in a greatly efficient tool to manage soil occupation and uses all around the world. Following this modeling of a process to mapping and quantifying mangrove areas, became an important step to creation and exercise of actions to conserve the remnant mangrove areas. Using RapidEye images of the interest areas, and applying the software ERDAS Imagine Professional to geoprocess the images, we found 25626,24 hectares of mangrove in the Sergipe State. The value found corresponds to 1,17% of the total territorial area. The actual mangrove areas are concentrated on four regions. These regions are located around the Piauí, Vaza Barris, Sergipe e São Francisco rivers.Pages: 4914-491
Queimadas na Amazônia Oriental em anos de Seca Extrema: fontes de combustível e propágulo de incêndios florestais
No full textThis paper aims to identify the fuel sources to burn scars and the sources of ignition responsible for forest fires that occur in the Eastern Amazon region (Pará State) during extreme drought scenarios. To reach this goal, were used deforestation maps provided by PRODES, a land use map from 2008 by the TerraClass project and maps of burn scars that occurred in 2005 and 2010. PRODES and TerraClass data were combined to generate 2005 and 2010 land use maps. Then, these maps were overlaid with 2005 and 2010 burn scar maps. It was observed that grasslands used as pastures were the major source of fuel for fires in the Eastern Amazon. This land use concentrates more than 30% of the burned area in 2005 and 2010, with a total burned area of 21 500 km2 and 43 000 km2, respectively. Burning in Forest areas was also representative in 2005 and 2010, with 24% and 27% of the burned area, respectively. Regarding the sources of ignition in forest fires, and considering only the burnt areas within a 2 km buffer distance from forest edges, burning in pastures was the main propagation source of fire in Forest areas. These results show that the environmental policies of "zero deforestation" do not eliminate the global contribution of Amazon greenhouse gases; it is necessary to create policies for more sustainable and less predatory land management than the use of fire.Pages: 6230-623
Análise da relação entre os perfis de NDVI obtidos dos sensores AVHRR/NOAA e MODIS nas áreas produtoras de cana-de-açúcar em São Paulo
No full textThe production of cane sugar in Brazil, in general, has been growing in recent years and has increasingly strategic role in the economy. Thus, it is important to propose innovative and technologically feasible solutions to help the generation of more efficient, objectives, precise, early and adequate models to monitoring and forecasting of the national crop. This study has the main objective of compare NDVI data from AVHRR/NOAA and MODIS/TERRA in productive sugarcane areas in São Paulo, from April 2001 to March 2010. Initially, were made the selection of sugarcane planting points in São Paulo and the extraction of NDVI profiles from AVHRR/NOAA and MODIS/TERRA. After that, clustering analysis using K-Medoids and DTW were made in 5 clusters with NDVI profile and, finally, the statistical analysis (Pearson correlation) done with clusters of the planted area, harvested area and crop yield. The clusters identified pixels related to the sugarcane planting areas and spectral mixture. The MODIS/TERRA showed values of R greater than the AVHRR/NOAA, because the sensor has a spatial resolution of 250m, with more details of sugarcane areas. However, the AVHRR/NOAA also obtained satisfactory results. This shows that it is possible to use data from low spatial resolution sensors to monitor and follow harvests of crops planted over large areas. The advantage of these sensor systems is their high temporal resolution, low cost and global coverage.Pages: 640-64