National Institute for Space Research
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Estimativa do saldo de radiação na cidade de Montes Claros/MG através de imagens do LANDSAT-5/TM
No full textThe net radiation is a major component of the energy balance and represents the energy available in surface heating processes related to air and soil, and is correlated withthe estimated evapotranspiration. The high costof field experimentsformeasuring this parameter, andthe difficultiesinmeasuring itto the surface, forces the search foralternative techniquesto complementthe meteorological dataavailablein order toassistfarmersindecision-making processes, especiallyin irrigated agriculture. In this context, the study aimed to estimate and spatializing net radiation through satellite imagery, to the city of Montes Claros, located in the North of Minas Gerais, on 21/09/2011. The images used were obtained from Landsat-5/TM stock images from National Institute for space research/INPE whose processing was performed in digital software ENVI4.7 and 5.2.1SPRING, including geometric corrections, radiometric and atmospheric. For the calculation of net radiation was calculated spectral radiance, reflectance, albedo at the top of the atmosphere, surface albedo, the index calculationsNDVI, SAVIand LAI, surface emissivity, obtaining the surface temperature, estimation of long wave radiation up ward, downward shortwave and longwave radiation. The results indicate that for the city of Montes Claros, the net radiation showed an average value of 445.31Wm-2, with 87.95% of its pixels to values of 326.06 Wm-2 to 655.589Wm-2. The values obtained are consistent with those found in the literature. Thus methodology becomes feasible to use additional information to areas where weather data are scarce, thereby supplying an important step to obtain evapotranspiration.Pages: 648-65
Uso do Sensor HRG - SPOT 5 e técnicas de processamento de imagens para caracterizar e avaliar a mudança da cobertura vegetal no estado de Rondônia
No full textThis paper aims to show the use of high-resolution orbital data on current survey of vegetation, emphasizing the quality of information derived from techniques digital image processing based on Linear Spectral Mixture Model and classification of land use in images HRG sensor, SPOT 5 satellite. This was linked to the existing information on land cover to understand the changes of land use in a watershed area used as experimental. The results of this study showed that there is quality in the data obtained by digital image processing as evidenced by the Kappa index. In a spatiotemporal correlation of vegetation was detected in the experimental area that Anthropic Areas declined significantly, increasing the number of areas with vegetation and forest regeneration.Pages: 7321-732
Desarrollo de un modelo generalizado para la estimación de la radiación neta diaria a partir de datos meteorológicos y de satélite
No full textNet radiation (Rn) is a key quantity for the estimation of surface energy budget and is used for various applications including climate monitoring, weather prediction and agricultural meteorology. Remote sensing provides an unparallel spatial and temporal coverage of land, thus several studies have attempted to estimate net radiation by combining satellite and meteorological data. Satellite imagery provides instantaneous data but in general it needs to have daily Rn values. There are several models to estimate daily Rn from satellite images but these are only applicable under certain conditions that are related to the time of image acquisition, the study region (latitude) and/or the time of year. In this work we proposed a generalized model to estimate daily net radiation using satellite and meteorological data. Measures collected at eight measurement campaigns (between March 2007 and June 2010) on the central-southeastern area of Buenos Aires province, Argentina, were used in this study. Preliminary results show good agreement between estimated and observed values of the daily Rn. Landsat images were used to show the applied the proposed model. Results indicate that the proposed model have better performance than others models, and in addition it is applicable to any satellite mission that allows us to obtain previously instantaneous net radiation.Pages: 297-30
Programas de Monitoramento Ambiental aplicados na Sub-Região Baixo Tapajós e Vale do Jamanxim, estado do Pará
No full textThe study area of this work includes two sub-regions covered by the BR-163 road, which is Baixo Tapajós and Vale do Jamanxim. This region was monitored from Environmental Monitoring Programs of the Federal Government. This study presents results of anthropism data from ProAE 2012 for Special Areas and deforestation data from PRODES / INPE 2011 applied to the remainder. After structuring the database, software R 2.13.2 was used to generate histogram of frequency of the investigated variables (anthropism, roads and drainage), from synchronization with the database created in Terra View 4.1.0. Non-Special Areas represents 43,7% of the investigated area, and according PRODES 2011 presents 1.212.693,00 hectares of deforestation accumulated, that is, 20,00% of total. Special Areas occupies 57,3% of the investigated territory, and ProAE 2012 identified 319.320,76 hectares of anthropism, which equates to 3,92%. The frequency histograms: percentage of anthropism, presence of roads and drainage, for Special and Non-Special Areas, pointed to the same pattern between anthropism and roads, rather than drainage. Despite anthropism rates are lower within the Special Areas, there is still a high human pressure therein, as it presents ProAE 2012 results. These protected areas are forest, mineral and biodiversity reserve, bringing the challenge consolidation of environmental management in this region.Pages: 6853-686
Modelagem da dinâmica do uso e ocupação do solo (1985-2011) na sub-bacia hidrográfica do Rio Novo-SP: Land Change Modeler-LCM
No full textThis paper had the objective to identify the processes of land use and cover changing by multitemporal analysis of Landsat TM images of 1985 and 2011 and through the Land Change Modeler module LCM-Idrisi Selva. It was observed during the 26 years the advancement of the urban area, the high demand of reforestation and reducing areas of native forest and pasture. In 1985 the urban area of Itatinga city was 134 ha, with urban sprawl had a gain totaling 166.3 ha 283.7 ha in 2011.The class was reforestation of 106.8 ha in 1985 rising to 598.5 ha in 2011. The results presented in this study, data gain, loss and persistence of classes of land use between the years studied, identified major changes in terms of quantity and spatial distribution. In this sense the Land Change Modeler module-LCM processes has the potential to predict when it relates to changes in land use and occupation. The temporal analysis from 1985 to 2011 enabled a better understanding of the environmental pressures to natural areas. This process proved to be of great importance since the change in complex and dynamic environments occur not only in its biological or natural, but also involves various aspects of anthropogenic and their interrelationships.Pages: 6222-622
ImgTools: a software for optical remotely sensed data analysis
No full textNeste artigo apresentamos as principais ferramentas de processamento de imagens de satélites da versão beta do software ImgTools. ImgTools foi desenvolvido para ser usado nos projetos de pesquisa e de monitoramento florestal do Imazon, mas rapidamente chamou a atenção de uma comunidade de usuários beta que começaram a testar e a usar o programa em seus projetos. A carência de programas comerciais ou de domínio publico com ferramentas integradas para normalização de dados multi-espectrais, de diferentes sensores remotos, com classificadores automáticos genéricos, foi a principal motivação para o desenvolvimento do software. Apresentamos também exemplos de projetos que utilizam o ImgTools e o desenvolvimento futuro do software.Pages: 1571-157
Levantamento do potencial de profissionais brasileiros especializados no emprego do geoprocessamento
No full textThe development of this work is part of a reality inside geotechnology companies with the need to be prepared, with qualified professionals, to attend the demand of workplaces on geography among other sciences. A surveillance was realized with 347 professionals of several cities of Brazil, which were selected by CNPQ (Conselho Nacional de Desenvolvimento Científico e Tecnológico) Lattes plataform, the networking website Linkedin and information coming from sources such as congresses and symposiums. The professionals were contacted via email and received a digital questionnaire to answer the questions regarded in this research. The data was processed and published by the ArcGis online software, where it was shared with Web Maps users. This way, in the development of this work, we seek to make available all the workers characteristics and bring back to discussion the challenges to lift off these qualified professionals as well the employment of geography as a knowledge basis for the understanding of the organizational business procedures.Pages: 2541-254
Aplicación de una metodología a partir del Modelo de Elevación Digital ASTER para la estimación de volúmenes de agua asociados a inundaciones en la región de Paraná, Entre Ríos, Argentina
No full textA la hora de analizar eventos severos como pueden ser inundaciones, las herramientas más confiables son la tecnología satelital o sensoramiento remoto y el uso de modelos hidrológicos. Estos eventos tienen un fuerte impacto sobre la región de la Cuenca del Plata debido al incremento en la intensidad y frecuencias de las precipitaciones en los últimos años y debido a la pequeña pendiente del terreno. El objetivo de este trabajo consiste en comparar la estimación de volúmenes de agua asociados a inundaciones a partir de una metodología que asume como base el uso del Modelo de Elevación Digital ASTER, con los resultados obtenidos de excesos de agua para los primeros niveles del terreno del modelo hidrológico CLASS U3M 1D. Se analizaron tres imágenes Landsat 5 TM de banda 7 para obtener, en una primera instancia, el valor del área inundada en cada fecha particular. Luego, se propuso una metodología a partir del Modelo de Elevación Digital ASTER para obtener el volumen de agua de estas áreas inundadas y así, también obtener la lámina de agua. Los resultados mostraron que la metodología propuesta tiende a sobreestimar los valores de lámina de agua con respecto al CLASS U3M 1D. Sin embargo, al contrastar temporalmente entre un día y otro, los resultados fueron muy positivos, dando valores de 0.53 m para el DEM y de 0.54 m para el modelo hidrológico. Por lo tanto, se puede concluir que la metodología es confiable para un análisis temporal de la situación analizada.Pages: 5628-563
Análise do uso do Modelo Linear de Mistura Espectral (MLME) para o mapeamento das áreas queimadas no Estado de Rondônia no ano de 2010
No full textThe biomass burning cause local impacts in land use and land cover and in biodiversity, altering the regional and global climate due to modification in energy balance of the atmosphere and of surface. Therefore, the objective of this work is to estimate the burned areas in Rondonia State for 2010 using Linear Spectral Mixture Model (MLME) in images of surface reflectance (MOD09GA and MOD09GQ) of MODIS sensor. Moreover, the results derived from MLME were assessed with data considered as reference obtained from the mapping of burned areas in Thematic Mapper (TM) sensor of Landsat 5 Satellite images. The results showed that from August to October 2010, the study area showed a total of 13,869 km2 of burned areas. Regarding the results of MLME compared with reference images, it was noticed that the maps were very similar, with an exception that showed a commission of 271% in mapped burned areas derived from MLME images. This large difference can be explained by the temporal resolution of the sensors, due to lack of available images of TM/Landsat 5. Also, lack of images in October and high incidence of clouds were the main source of errors. Therefore, it was noticed that MLME constitute an important tool and could be used to derive burned areas in larger areas or in long temporal series.Pages: 7265-727
Geração de modelos digitais do terreno por interferometria SAR: avaliação dos sensores aerotransportados SAR/R99B e OrbiSAR RFP
No full textOne of the main demands of SAR imaging constitutes the generation of DEM's by the interferometry. This technique is the simultaneous acquisition of two images, through two antennas, in one passage or two, separated by a distance known as the base line. Operating in the X, L and P bands, the SAR/R99B and OrbiSAR RFP, presents, respectively, in R99B aircraft of the brazilian air force, and a Turbo Commander 690 aircraft, owned by the OrbiSat company, has conducted many surveys, producing large-scale data. The DEM's generated by the sensors cited, presents spatial resolution and altimetric precision of 5 meters, the SAR/R99B data, which generates its DEM's from the X band, has many problems to be overcome, there are few imaging, and still need many adjustments to its full operationalization, problems like shadows in slopes areas need correction, but it is an important tool that still needs more studies to evaluate their applications. The OrbiSAR RFP data, they have different ways of generating DEM's, operating in X-band and P, generating models at ground level and models at the level of top of the trees in forest areas. This sensor is already operational and is working on mapping the Brazilian Amazon, mapping the topography of the ground of forest using P-band. With the operational availability of both sensors, working at the same level of positional accuracy, altimetry, and spatial resolution of the products generated, the gain for the imaging of large areas, such as the mapping of the Brazilian Amazon, is huge.Pages: 8499-850