@MastersThesis{Petri:2019:AvDaMO,
author = "Petri, Caio Arlanche",
title = "Avalia{\c{c}}{\~a}o de dados MODIS (MAIAC) corrigidos e
n{\~a}o-corrigidos para efeitos bidirecionais na Amaz{\^o}nia",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2019",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2019-02-13",
keywords = "MODIS, efeitos bidirecionais, s{\'e}ries temporais,
{\'{\i}}ndices de vegeta{\c{c}}{\~a}o, MODIS, bidirectional
effects, time series, vegetation indices.",
abstract = "Estudos de florestas tropicais da Amaz{\^o}nia t{\^e}m se
beneficiado da s{\'e}rie temporal relativamente longa de
{\'{\i}}ndices de vegeta{\c{c}}{\~a}o (IVs) produzida pelo
sensor MODIS (Moderate Resolution Imaging Spectroradiometer).
Entretanto, por ser um sensor com amplo campo de visada, as
s{\'e}ries temporais s{\~a}o afetadas por efeitos bidirecionais,
mesmo quando produtos compostos de 16 dias s{\~a}o utilizados. O
objetivo deste trabalho foi analisar a magnitude dos efeitos
bidirecionais na Amaz{\^o}nia sobre a determina{\c{c}}{\~a}o de
sete IVs e da reflect{\^a}ncia das respectivas bandas do MODIS
que comp{\~o}em estes {\'{\i}}ndices. O Cerrado foi usado como
{\'a}rea de refer{\^e}ncia para compara{\c{c}}{\~a}o dos
resultados. Usando o algoritmo MAIAC (Multi-Angle Implementation
of Atmospheric Correction) para corre{\c{c}}{\~a}o dos efeitos
atmosf{\'e}ricos e de BRDF, sete IVs foram calculados explorando
diferentes intervalos espectrais e significados
biof{\'{\i}}sicos: EVI (Enhanced Vegetation Index), GRND
(Green-Red Vegetation Index), NDII (Normalized Difference Infrared
Index), NDVI (Normalized Difference Vegetation Index), NDWI
(Nomalized Difference Water Index), PRI (Photochemical Reflectance
Index) e SWND (SWIR Normalized Difference). Para a an{\'a}lise
comparativa dos fatores potencialmente causadores de efeitos BRDF
na Amaz{\^o}nia e no Cerrado, foram avaliados dados de
{\^a}ngulo zenital de visada (AZV), {\^a}ngulo zenital solar
(AZS), {\^a}ngulo azimutal relativo (AAR) e dire{\c{c}}{\~a}o
de imageamento, al{\'e}m das condi{\c{c}}{\~o}es
atmosf{\'e}ricas no momento de aquisi{\c{c}}{\~a}o das imagens
(qualidade radiom{\'e}trica dos pixels). Para an{\'a}lise dos
efeitos BRDF sobre a reflect{\^a}ncia e IVs, foram consideradas
mudan{\c{c}}as percentuais relativas, testes
n{\~a}o-param{\'e}tricos (Mann-Whitney U), m{\'e}tricas de
Cohen e dist{\^a}ncias angulares entre dados corrigidos e
n{\~a}o-corrigidos. Finalmente, ap{\'o}s corre{\c{c}}{\~a}o
BRDF, comparou-se o comportamento sazonal dos sete IVs entre si,
usando tamb{\'e}m dados de GPP (Gross Primary Production) e LUE
(Light Use Efficiency) de tr{\^e}s torres de fluxo na
Amaz{\^o}nia (Bel{\'e}m, Manaus e Santar{\'e}m). Os principais
resultados mostraram que: (a) As condi{\c{c}}{\~o}es
atmosf{\'e}ricas de observa{\c{c}}{\~a}o na Amaz{\^o}nia
tornam este ecossistema mais suscet{\'{\i}}vel a efeitos BRDF
quando comparado com {\'a}reas de Cerrado, mesmo considerando as
mudan{\c{c}}as sazonais mais fortes na vegeta{\c{c}}{\~a}o
sav{\^a}nica; (b) O EVI e o PRI foram os IVs mais
sens{\'{\i}}veis aos efeitos BRDF, em uma avalia{\c{c}}{\~a}o
conjunta das an{\'a}lises estat{\'{\i}}sticas adotadas; (c)
EVI, NDII e NDWI acompanharam os dados de GPP de torres de fluxo
na Amaz{\^o}nia, durante a esta{\c{c}}{\~a}o seca, mas nem
todos os IVs mostraram resposta biof{\'{\i}}sica consistente
entre si. De forma geral, o presente estudo contribui para uma
melhor compreens{\~a}o dos efeitos BRDF sobre a reflect{\^a}ncia
de bandas e IVs do MODIS. ABSTRACT: Studies of tropical
rainforests from the Amazon have benefited from the relatively
long time series of vegetation indices (VIs) produced by the MODIS
(Moderate Resolution Imaging Spectroradiometer) sensor. However,
because MODIS is a sensor with a large field of view, the time
series is affected by bidirectional effects, even when 16-day
composite products are used. The objective of this work was to
analyse the magnitude of the bidirectional effects in Amazonia on
the determination of seven VIs and on the reflectance of the
respective MODIS bands that compose these indices. The savannas
from the Brazilian Cerrado were used as reference areas for
comparison of results. Using the MAIAC (Multi-Angle Implementation
of Atmospheric Correction) for the correction of atmospheric and
BRDF effects, seven VIs were calculated by exploring different
spectral ranges and biophysical meanings: EVI (Enhanced Vegetation
Index), GRND (Green-Red Vegetation Index), NDII (Normalized
Difference Infrared Index), NDVI (Normalized Difference Vegetation
Index), NDWI (Normalized Difference Water Index), PRI
(Photochemical Reflectance Index) and SWND (ShortWave infrared
Normalized Difference). For the comparative analysis of the
factors that could cause BRDF effects in the Amazon and the
Cerrado, view zenith angle (VZA), solar zenith angle (SZA),
relative azimuth angle (RAA), viewing direction and atmospheric
conditions during image acquisition (radiometric quality of the
pixels) were evaluated. For the analysis of BRDF effects on
reflectance and VIs, relative percentage changes, non-parametric
(Mann-Whitney U) tests, Cohen metrics and angular distances
between corrected and uncorrected data were considered. Finally,
after BRDF correction, the seasonal behaviors of the seven VIs
were compared to each other, also using GPP (Gross Primary
Production) and LUE (Light Use Efficiency) data from three
Amazonian flux towers (Bel{\'e}m, Manaus and Santar{\'e}m). The
main results showed that: (a) The atmospheric conditions in the
Amazon make this ecosystem more susceptible to BRDF effects than
the Cerrado, even considering the stronger seasonal changes
observed in the savanna-like vegetation; (b) EVI and PRI were the
most sensitive VIs to BRDF effects in a joint evaluation of the
adopted statistical analyses; (c) EVI, NDII and NDWI followed the
GPP pattern observed in flux towers of the Amazon during the dry
season, but some VIs did not show consistent biophysical response
to each other. In general, this study contributes for better
understanding the BRDF effects on the reflectance of bands and VIs
of MODIS.",
committee = "Ponzoni, Fl{\'a}vio Jorge (presidente) and Galv{\~a}o,
L{\^e}nio Soares (orientador) and Renn{\'o}, Camilo Daleles and
Breuning, F{\'a}bio Marcelo",
englishtitle = "Evaluation of MODIS data (MAIAC) data corrected and noncorrected
for bidirectional effects in the Amazon",
language = "pt",
pages = "97",
ibi = "8JMKD3MGP3W34R/3SK3KRB",
url = "http://urlib.net/ibi/8JMKD3MGP3W34R/3SK3KRB",
targetfile = "publicacao.pdf",
urlaccessdate = "25 abr. 2024"
}