Power spectrum analysis of SAR data for spatial forest characterization in Amazonia

Neeff, Till; Dutra, Luciano Vieira; Santos, João Roberto dos; Freitas, Corina da Costa; Araujo, L. S. de

doi:10.1080/01431160500104301

Cited by 20 publications

(12 citation statements)

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“…A aplicabilidade dos dados SAR, quanto à relação e análise dos seus diversos atributos, decomposição de alvos e algoritmos classificatórios polarimétricos, tem um vasto campo científico: desde a questão de caracterização da tipologia florestal e mapeamento temático (Van der Sanden e Hoekman 1999; Santos et al 2008); a questão de análise de respostas polarimétricas de alvos florestais (Mc Nairn et al 2002;Santos et al 2009); os estudos de parâmetros biofísicos para a modelagem volumétrica e de biomassa (Santos et al 2002;Neeff et al 2005a;Neeff et al 2005b;Saatchi et al 2007;Gonçalves et al 2011); até o uso específico de classificadores polarimétricos no delineamento de classes de uso e cobertura da terra, como os trabalhos de: Freitas et al (2008) …”

Section: Síntese Teórica Dos Conceitos Sar E Suas Aplicações Em Estudunclassified

Análise do potencial de imagem TerraSAR-X para mapeamento temático no sudoeste da Amazônia brasileira

et al. 2012

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ResumoO presente trabalho tem como objetivo analisar o potencial de imagens SAR polarimétricas do sensor TerraSAR-X, no modo StripMap, para mapear o uso e cobertura da terra na região sudoeste da Amazônia brasileira. No procedimento metodológico imagens de amplitude nas polarizações A HH e A VV , A derivada da matriz de covariância, bem como da entropia A Entropia derivada da decomposição de alvos por auto-valores fizeram parte, de forma individual ou combinada, do conjunto de dados investigados. Na classificação das imagens foram empregados dois classificadores: um baseado nas funções estatísticas de máxima verossimilhança (MAXVER); e outro, o método contextual (Context). Os resultados temáticos dessas classificações foram avaliados através da matriz de confusão e pelo índice Kappa. De forma sintetizada pode-se afirmar que as componentes A e A Entropia , têm significativa contribuição no procedimento classificatório, sobretudo pelo método Context, cujo desempenho alcançou com 78% de exatidão global e índice Kappa de 0,70.PalavRas-chave: mapeamento florestal, radar, classificação polarimétrica, Amazônia. Analysis of the potential use from TerraSAR-X images for thematic mapping in SW Brazilian Amazon region abstRactThe objective of this work was to analyze the potential use of SAR polarimetric images from the TerraSAR-X sensor system, at StripMap mode, to map land use and land cover in SW Brazilian Amazon. Amplitude images at polarizations A HH , A VV , A , derived from the co-variance matrix, as well as the entropy A Entropia , derived from the decomposition of targets by eigenvalues, are parts of the datasets investigated individually or in combined form. Two classifiers were used: the first is based on statistical functions of maximum likelihood (MAXVER), and the second is the contextual method (Context). The thematic results from these classifications were evaluated by a confusion matrix and by the Kappa index. Summarizing we can state that the components A and A Entropia , gave a significant contribution to the image classification procedure, considering specially the Context method, whose performance reached 78% of Global Accuracy and a Kappa index of 0.70.

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Section: Síntese Teórica Dos Conceitos Sar E Suas Aplicações Em Estudunclassified

Análise do potencial de imagem TerraSAR-X para mapeamento temático no sudoeste da Amazônia brasileira

et al. 2012

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“…Spectral analysis is a powerful tool to analyze historical series, and although not many studies have used it for water quality data series, it is already commonly used for environmental data series analysis (NEEFF et al, 2005;MENEZES;PESSANHA, 2014).…”

Section: Introductionmentioning

confidence: 99%

Spectral analysis in determining water quality sampling intervals

Silva

Silveira

2019

RBRH

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To make water quality series more representative, real-time monitoring techniques are developed. However, these techniques have obstacles in their use, such as high costs and difficulties in equipment installation, maintenance, and calibration. One alternative is near-real time water quality monitoring (NRTWQM), with sampling done less frequently than daily. The study objective was to evaluate, through spectral analysis, the water quality sampling frequency representativity for different catchments. For this purpose, a historical series of real time water quality monitoring stations were used in Brazil, Canada, and the USA. These series were submitted to spectral analysis to identify the denser frequencies and their representativeness across the series. To obtain the sampling intervals, the Nyquist-Shannon theorem was applied. Weekly intervals accounted for 65% of cumulative frequencies for the three verified parameters, and the sampling intervals obtained by means of the characteristic frequencies were shown to be executable in the NRTWQM models for up to the 90% of cumulative frequency. For cumulative frequency above 90%, the intervals approach the daily values.

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“…Power spectrum analysis was used for the analysis of spatial forest features (canopy structure and distances between major tree individuals) from airborne SAR (X-band) data in the Brazilian Amazon (Neeff et al, 2005b). Hoekman and Quiñones (2000), Hawkins et al (2000), and Santos et al (2002; specifically estimated forest biomass, and discussed backscatter saturation caused by the high-density of tropical forests.…”

Section: Introductionmentioning

confidence: 99%

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2006

Ambi-Agua

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Obs.: 1) A lista inclui revisores que avaliaram mais de um artigo.2) A lista inclui revisores de artigos que foram rejeitados ii ix ÍNDICE CAPA Foz do Rio Tapajós e trecho do Rio Amazonas entre Óbidos e Santarém, PA. As linhas tracejadas representam a faixa de dados imageada pelo sensor Hyperion. O gráfico embaixo à esquerda mostra as hidrógrafas do Rio Amazonas, em Óbidos para os anos de 2001 e 2005. Fonte: RUDORFF, C. M.; NOVO, E. M. L. M; GALVÃO, L. S. G. Spectral mixture analysis for water quality assessment over the Amazon floodplain using Hyperion/EO-1 Images. EDITORIAL 11 Publicação Científica (doi:10.4136/ambi-agua.8) Getulio Teixeira Batista ARTIGOS SAR data for the analysis of forest features: current Brazilian experiences (doi:10.4136/ambi-agua.9) 15 João Roberto dos Santos; Fábio Furlan Gama; Fábio Guimarães Gonçalves Monitoramento e estimativa da produtividade de soja auxiliados pelo modelo regional de previsão de tempo ETA (doi:10.4136/ambi-agua.10) 28 Modelagem do volume e do peso da casca de Bracatinga (Mimosa scabrella -Bentham) na região metropolitana de Curitiba, Paraná (doi:10.4136/ambiagua.11) 39 Sebastião do Spectral mixture analysis for water quality assessment over the Amazon floodplain using Hyperion/EO-1 images (doi:10.4136/ambi-agua.13) 65 Conrado de Moraes Rudorff; Evlyn Márcia Leão de Moraes Novo; Lênio Soares Galvão Avaliação do desempenho de diferentes classificadores (Isoseg, Bhattacharyya, Maxver e Maxver-ICM), utilizando imagens CCD/CBERS-1 e ETM+/Landsat-7 fusionadas (doi:10.4136/ambi-agua.14)80 the first volume, the editorial board of Ambi-Água has the satisfaction of manifesting that the continuous interaction with the authors and reviewers resulted in a minimum processing time from the submission to the journal issue publication. Palavras-chave: estrutura florestal; SAR; inventário florestal; sensoriamento remoto; floresta tropical; Eucalyptus sp.; modelagem florestal. ABSTRACTVegetation indices (NDVI and EVI) obtained from MODIS products (25m and 50m, surface reflectance) were evaluated in relation to the possibility of detecting and monitoring deforestation areas in Amazonia. A new vegetation index, the DNRG (Normalized Difference between Red and Green spectral bands), was proposed with the same objective. The radiometric quality of the multi-date MODIS products was evaluated to verify the possibility of using vegetation index to generate deforestation maps. The internal accuracy of multi-date composites were evaluated providing a value of positional error less than 1 pixel (< 25m) and, consequently geometric corrections were not necessary. The potential of surface reflectance MODIS products was evaluated in the region of Terra do Meio (Pará State, Brazil, between latitudes 06°00'S to 08°00'S and longitudes 51°00'W to 54°00'W), using the Euclidian minimum distance supervised algorithm of classification. Global accuracies above 87% were CORREIA, A. H.; FORMAGGIO, A. R.; SHIMABUKURO, Y. E.; DUARTE, V. Avaliação de índices de vegetação MODIS para detecção de desmatamentos na A...

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Power spectrum analysis of SAR data for spatial forest characterization in Amazonia

Cited by 20 publications

References 14 publications

Análise do potencial de imagem TerraSAR-X para mapeamento temático no sudoeste da Amazônia brasileira

Análise do potencial de imagem TerraSAR-X para mapeamento temático no sudoeste da Amazônia brasileira

Spectral analysis in determining water quality sampling intervals

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