AVALIAÇÃO DE IMAGENS SIMULADAS DA CÂMERA MUX DO SATÉLITE CBERS-4 APLICADAS À ANÁLISE AMBIENTAL

Métodos de simulação de imagens orbitais são frequentemente utilizadas naavaliação do desempenho de determinado sistema-sensor. A partir do empregodestas técnicas é possível analisar e estimar o comportamento das imagens que serãogeradas pelos sensores projetados, possibilitando uma estimativa da qualidade e dasaplicações decorrentes do lançamento do satélite. Neste contexto, torna-se defundamental importância a análise das imagens orbitais e das possíveis aplicaçõesprovenientes do satélite CBERS-4, que deve ser lançado ao final do ano de 2014 eterá uma política de distribuição gratuita dos dados. Deste modo, o objetivo destetrabalho é avaliar o potencial da câmera MUX do CBERS-4, com 20 m de resoluçãoespacial, para mapeamento de cobertura do solo do município de Apuí no estado do Amazonas. Para isto, as imagens MUX são simuladas a partir de imagens do satéliteRapidEye e filtragem baseada no modelo do processo de imageamento. Para avaliaros resultados da simulação, uma imagem da câmera TM do satélite Landsat-5 éprocessada para produzir um mapa de cobertura de solo, que é comparada ao mapagerado pela imagem MUX simulada do CBERS-4. Os valores de NDVI calculadosa partir das imagens MUX simulada e TM-5 também são analisados. Osexperimentos mostram que o processamento das imagens simuladas da câmeraMUX apresentaram resultados semelhantes aos das imagens do sensor TM. Emgeral, as classificações da cobertura do solo para os sensores MUX e TMapresentam boa concordância, com acurácia global de 87% e Kappa de 0,72. Ainda,percebe-se que os valores de NDVI estimados pela MUX são em média 25%maiores que os valores estimados pelo TM e apresentam uma correlação de 85%(significante a 0.05, teste t-student)

Utilização de técnicas de geoprocessamento para avaliação da cobertura e uso do solo do município de Jataí – GO

Covering approximately 25% of the country, the savanna is a biome that most suffer from human activity. According to Sano et al. (2002), approximately 40% of native areas of this biome has been converted to agropastoral activities. The soil cover is very important to present the actual state of vegetation and degradation state of the landscape in the studied area. The use of satellite images is one of the only ways, if not the only one, to get the mapping of large areas at different time intervals with reduced costs. Due to high technologies, currently houses the cerrado, in the case of agricultural crops, extensive plantings of soybeans, corn, beans, cotton, coffee and sugar cane. Current data show that about 50% of its area has been converted to cropland and the trend is that this occupation will increase each season, by its geographical and climatic conditions. Within the context of agriculture, Jataí is considered the largest grain producer in the State of Goiás, deserving special attention due to the technical management of agricultural soils. Using data obtained from the Geoprocessing technology, this work successfully made a monitoring of Jataí, aiming to map the deforestation occurring in this savanna between the period 1987 to 2010.Pages: 4533-453

Revisão de Métodos de Simulação de Imagens de Sensores Ópticos

The image simulation is important in all applications that need to work with different resolution images in order to compare the impact of the resolution change in visual or statistical terms. An important issue about images simulation is the quality or fidelity of the models. How well represent are the simulated images? The most natural response appears to be dependent of the application. Some applications need only change the pixel size of the image. Others need reproduce adequately the average radiation levels and all variations into the scene. Thus, it is concluded that the methods are, and indeed must be adjusted for each problem . This research intends to examine the simulation techniques, indicating which techniques is more feasible to the actual resource and data availability. It is also intended, to contribute in feasibility studies of future sensors, where the practice of developing simulation processes before sensor construction is very common to perform possible errors prediction.Pages: 8114-812

Simulação das bandas espectrais do sensor QuickBird-2 a partir do sensor WorldView-2

Data comparison between two different sensors must analyze one of their several characteristics. In order to evaluate the potential of the improvements on spectral resolution of WorldView-2 sensor, the reference data must have the same spatial and radiometric resolutions, besides the same geometric and atmospheric conditions of acquisition. For most areas throughout the world, there are no available images acquired by WorldView-2 and QuickBird-2 sensors in the same date or under the same geometric and atmospheric conditions. Therefore, the combination of the bands of given sensor to simulate the bands of a reference sensor represents an attractive possibility for the handling of remote sensing data, searching for its improvement. This work presents a methodology for the simulation of the multispectral bands of QuickBird-2 sensor applying the weighted combination of the spectral bands that possess spectral overlapping with each reference band of WorldView-2 sensor. The analysis of the spectral overlapping was performed through the discretizing of the spectral curves. Visual and statistical tests were accomplished to confirm the effectiveness of the methodology.Pages: 7981-798

Integração de Dados Ópticos e SRTM: Região de Brasília – DF

This paper aims to show the data integration from optical sensors (LANDSAT-7 ETM+ and CBERS- 2) with radar (SRTM), using a set of remote sensing tools in order to systematize them in such a way as to be useful in many applications. To this end, highlighted the use of different techniques of digital image processing, for generating an improved final product in its visual interpretation, trying to extract as much possible information from the data collected. The different integration data made by the IHS transformation, it constitutes an efficient technique for generating a final product that hold information obtained from different sensors. Fusion techniques allow to integrate the best spatial resolution panchromatic band with better spectral resolution of other bands, producing a color image that combines both characteristics. The Brasilia region was chosen as a case study and to that end, we carried out the integration of optical data of the area that had a better spatial resolution and radiometric radar data to obtain a better view altimetry. Was obtained as final products a hybrid image and a digital terrain model that showed a significant improvement in visual quality from them.Pages: 7880-788

AVALIAÇÃO DE IMAGENS SIMULADAS DA CÂMERA MUX DO SATÉLITE CBERS-4 APLICADAS À ANÁLISE AMBIENTAL

Métodos de simulação de imagens orbitais são frequentemente utilizadas na avaliação do desempenho de determinado sistema-sensor. A partir do emprego destas técnicas é possível analisar e estimar o comportamento das imagens que serão geradas pelos sensores projetados, possibilitando uma estimativa da qualidade e das aplicações decorrentes do lançamento do satélite. Neste contexto, torna-se de fundamental importância a análise das imagens orbitais e das possíveis aplicações provenientes do satélite CBERS-4, que deve ser lançado ao final do ano de 2014 e terá uma política de distribuição gratuita dos dados. Deste modo, o objetivo deste trabalho é avaliar o potencial da câmera MUX do CBERS-4, com 20 m de resolução espacial, para mapeamento de cobertura do solo do município de Apuí no estado do Amazonas. Para isto, as imagens MUX são simuladas a partir de imagens do satélite RapidEye e filtragem baseada no modelo do processo de imageamento. Para avaliar os resultados da simulação, uma imagem da câmera TM do satélite Landsat-5 é processada para produzir um mapa de cobertura de solo, que é comparada ao mapa gerado pela imagem MUX simulada do CBERS-4. Os valores de NDVI calculados a partir das imagens MUX simulada e TM-5 também são analisados. Os experimentos mostram que o processamento das imagens simuladas da câmera MUX apresentaram resultados semelhantes aos das imagens do sensor TM. Em geral, as classificações da cobertura do solo para os sensores MUX e TM apresentam boa concordância, com acurácia global de 87% e Kappa de 0,72. Ainda, percebe-se que os valores de NDVI estimados pela MUX são em média 25% maiores que os valores estimados pelo TM e apresentam uma correlação de 85% (significante a 0.05, teste t-student)

Simulação e Restauração de Imagens HRC CBERS 2B

Restoration is an image processing technique for correcting distortions inserted by sensor systems during the imaging process. Blurring is one of the most notable effects, which reduce the amount of information on the image. There are several restoration techniques presented in literature. However, the application of such filters depends intrinsically on the type of sensor, which leads to a comparison between techniques, in order to find the method that better fits the proposed sensor. An alternative for a comparison is image simulation. Through image simulation techniques it is possible to estimate characteristics from existing or planned sensors, enabling an assessment sensors performance or the quality of image processing techniques applied to these images. This work proposes the comparison of three restoration methods applied to HRC (High Resolution Camera) sensor, from, CBERS 2B (China Brazil Earth Resource Satellite) satellite: Wiener filter, Richardson- Lucy filter and Modified Inverse Filter. For the comparison, an image from HRC - CBERS 2B sensor is simulated using PRISM (Panchromatic Remote-sensing Instrument Mapping) sensor from ALOS (Advanced Land Observing System) satellite as input. Statistical measures show that Richardson-Lucy method outperforms the other two methods. Visual results of the simulation and restoration are also shown.Pages: 2652-266

Simulação de uma imagem WFI/CBERS-3 para a classificação de massas d’água no Reservatório de Ibitinga – SP

Even though currently there are a lot of sensors with adequate spectral and radiometric resolutions and field of view to the water properties characterization, the low spatial resolution limits the application of their images on the inland water study. The WFI sensor that will be launched at the CBERS-3 satellite may fill this gap by having spectral, radiometric and spatial characteristics that attend the application needs for inland water studies. To assess a sensor performance before its launch there are available image simulation methods. This article aimed to assess the potential of a WFI/CBERS-3 image to distinguish optically distinct water masses in the Ibitinga ReservoirSP. Therefore, it was accomplished the image simulation of this sensor from a QuickBird scene, which has similar spectral and radiometric properties to the WFI sensor. Unsupervised classifications were performed with different numbers of spectral classes for the simulated image and for a TM/Landsat-5 image (resampled to the same pixel size). It was realized that the application of high radiometric resolution images allows the obtaining of better results for the optically distinct water masses classification. However, the use of high spatial resolution images on the simulation process may complicate the water masses distinction due to the direct surface reflection of the Sun light. The surface water ripples caused by the wind action intensify the brightness in these images, damaging the classification. Nevertheless, the WFI/CBERS-3 image simulation indicated a high potential of this sensor to water quality studies in inland aquatic systems.Pages: 2530-253