Topographic Effect on Spectral Vegetation Indices From Landsat Tm Data: Is Topographic Correction Necessary?

Moreira, Eder Paulo; Valeriano, Márcio de Morisson; Sanches, I. D.; Formaggio, Antônio Roberto

doi:10.1590/s1982-21702016000100006

Cited by 18 publications

(8 citation statements)

References 30 publications

(39 reference statements)

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“…In relation to the topographic correction ( Figure 3) there was decreasing in R 2 values among the vegetation index and cosine factor (R 2 values close and / or equal zero) indicating a decrease in the dependence of the index on topographic effects. Similar results were observed by Moreira et al (2016). FIGURE 3.…”

Section: Analysis Of the Relationship Between Vis With And Without Cosupporting

confidence: 88%

Relationship Between Coffee Crop Productivity and Vegetation Indexes Derived From Oli / Landsat-8 Sensor Data With and Without Topographic Correction

2018

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The reflectance values of a coffee crop are influenced by several factors such as planting direction, crop spacing, time of the year, plant age and topography which reduces the accuracy of the estimates derived from remote sensing data. In this context were evaluated the relationships between coffee productivity and values of NDVI, SAVI and NDWI vegetation indexes with and without topographic reflectance correction for different coffee phenological phases for the crop years 2013/2014 (low productivity) and 2014/2015 (high productivity). The evaluations were made through the standard deviation of vegetation indices (VIs), linear relationship between the cosine factor and the VIs and between VIs and coffee productivity. The best phenological phases of coffee to determine productivity from spectral indexes were the stages of dormancy and flowering. The results indicated that the NDVI was the best index to estimate the productivity of coffee trees with coefficient of determination (R²) that ranged from 0.58 to 0.90. There was an increase in R² between productivity and NDVI with topographic correction in the dormancy phase in the year of low productivity; between productivity and NDVI with topographic correction in the flowering phase in the year of high productivity; and between productivity and SAVI and NDWI with topographic corrections in the flowering phase in the year of high productivity.

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Section: Analysis Of the Relationship Between Vis With And Without Cosupporting

confidence: 88%

Relationship Between Coffee Crop Productivity and Vegetation Indexes Derived From Oli / Landsat-8 Sensor Data With and Without Topographic Correction

2018

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“…Por fim, segundo Moreira et al (2016), a comparação entre índices de vegetação calculados com correção e sem correção topográfica demonstrou que o NDVI é menos sensível aos efeitos topográficos entre os outros índices estudados. O seu estudo conclui, assim, que a correção topográfica é necessária para a redução consistente do efeito topográfico em terrenos acidentados.…”

Section: Discussionunclassified

Análise Do Impacto Da Correção Atmosférica No Cálculo Do Índice De Vegetação Por Diferença Normalizada a Partir De Imagem Landsat 8/Oli

Francisco

Ruiz

Almeida

et al. 2020

Rev. Bras. Geog. Fis.

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As operações aritméticas efetuadas entre bandas espectrais de imagens de sensoriamento remoto necessitam de correção atmosférica para eliminar os efeitos atmosféricos na resposta espectral dos alvos, pois os números digitais não apresentam escala equivalente em todas as bandas. Índices de vegetação, calculados com base em operações aritméticas, além de caracterizarem a vegetação, minimizam os efeitos da iluminação da cena causados pela topografia. Com o objetivo de analisar a eficácia da correção atmosférica no cálculo de índices de vegetação, este trabalho comparou os Índices de Vegetação por Diferença Normalizada (Normalized Difference Vegetation Index - NDVI), calculados com base em imagens corrigidas e não corrigidas de um recorte de uma cena Landsat 8/OLI situado na cidade do Rio de Janeiro, Brasil. Os resultados mostraram que o NDVI calculado pela reflectância, ou seja, imagem corrigida, apresentou o melhor resultado, devido ao maior discriminação das classes de vegetação e de corpos d'água na imagem, bem como à minimização do efeito topográfico nos valores dos índices de vegetação. Analysis of the atmospheric correction impact on the assessment of the Normalized Difference Vegetation Index for a Landsat 8 oli image A B S T R A C TThe image arithmetic operations must be executed on previously atmospherically corrected bands, since the digital numbers do not present equivalent scales in all bands. Vegetation indices, calculated by means of arithmetic operations, are meant for both targets characterization and the minimization of illumination effects caused by the topography. With the purpose to analyze the efficacy of atmospheric correction in the calculation of vegetation indices with respect to the mitigation of atmospheric and topographic effects on the targets spectral response, this paper compared the NDVI (Normalized Difference Vegetation Index) calculated using corrected and uncorrected images related to an inset of a Landsat 8 OLI scene from Rio de Janeiro, Brazil. The result showed that NDVI calculated from reflectance values, i.e, corrected images, presented the best results due to a greater number of vegetation patches and water bodies classes that could be discriminated in the image, as well the mitigation of the topographic effect in the vegetation indices values.Keywords: remote sensing, urban forest, atmospheric correction.

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“…Processing the images interpretation is done in ENVI 5.1 software. Remote sensing data have become one of the important sources of information for studying vegetation, from global continental down to a local scale [43,44]. In particular, spectral vegetation indices are widely used for monitoring, analysing, and mapping temporal and spatial variations in vegetation structure and in biophysical parameters [45].…”

Section: Methodsmentioning

confidence: 99%

Geo-Environmental Estimation of Land Use Changes and Its Effects on Egyptian Temples at Luxor City

Elfadaly

Wafa

Abouarab

et al. 2017

IJGI

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Over the years, the Egyptian temples at Luxor city have been intensely investigated, but most of these studies just focused on the classical sides of the archaeological and historical descriptions. Many of the environmental problems are the inevitable results of the unplanned urban crawling around the monuments temples. This paper aims at assessing the environmental changes around some temples of Luxor City using remote sensing and GIS techniques. In particular, a historical database made up of Corona and Landsat TM data have been investigated along with the new acquisitions of Quickbird 2 and Sentinel 2. Results from our investigation highlighted rapid changes in urban and agricultural areas, which adversely affected the Egyptian monumental temples causing serious degradation phenomena. Using the information obtained from our RS&GIS based analysis, mitigation strategies have been also identified for supporting the preservation of the archaeological area.

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Topographic Effect on Spectral Vegetation Indices From Landsat Tm Data: Is Topographic Correction Necessary?

Cited by 18 publications

References 30 publications

Relationship Between Coffee Crop Productivity and Vegetation Indexes Derived From Oli / Landsat-8 Sensor Data With and Without Topographic Correction

Relationship Between Coffee Crop Productivity and Vegetation Indexes Derived From Oli / Landsat-8 Sensor Data With and Without Topographic Correction

Análise Do Impacto Da Correção Atmosférica No Cálculo Do Índice De Vegetação Por Diferença Normalizada a Partir De Imagem Landsat 8/Oli

Geo-Environmental Estimation of Land Use Changes and Its Effects on Egyptian Temples at Luxor City

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