@MastersThesis{Moreira:2000:InPoLa,
author = "Moreira, Romero da Costa",
title = "Influ{\^e}ncia do posicionamento e da largura de bandas de
sensores remotos e dos efeitos atmosf{\'e}ricos na
determina{\c{c}}{\~a}o de {\'{\i}}ndices de
vegeta{\c{c}}{\~a}o",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2000",
address = "Sao Jose dos Campos",
month = "2000-05-08",
keywords = "vegeta{\c{c}}{\~a}o, Mato Grosso Do Sul (MS), espectr{\^o}metro
imageador aerotransportado do vis{\'{\i}}vel e infravermelho,
AVIRIS, {\'{\i}}ndice de vegeta{\c{c}}{\~a}o, analise
espectral, contraste de imagens, infrared spectrometers,
vegeetative index, spectrum analysis, image contrast.",
abstract = "Investigou-se a influ{\^e}ncia do posicionamento e da largura das
bandas do Vermelho (V - 600 a 700 nm) e do Infravermelho
pr{\'o}ximo (IVP - 750 a 1100 nm), assim como a influencia da
atmosfera, na determina{\c{c}}{\~a}o dos {\'{\i}}ndices de
vegeta{\c{c}}{\~a}o (IVs) NDVI, SAVI e ARVI, obtidos a partir de
dados hiperespectrais do sensor Airborne Visible/InfraRed Imaging
Spectrometer (AVIRIS). Com base no uso do c{\'o}digo MODTRAN, os
dados originais de radi{\^a}ncia aparente foram convertidos para
imagens {{"}reflect{\^a}ncia} de superf{\'{\i}}cie\{"} e
{{"}reflect{\^a}ncia} aparente\{"}. Os IVs foram obtidos para
esses dois conjuntos de dados, considerando-se tr{\^e}s espectros
de referencia representativos dos alvos Vegeta{\c{c}}{\~a}o
Verde (VV), Vegeta{\c{c}}{\~a}o N{\~a}o-fotossinteticamente
ativa (VNFA) e Solo (S), selecionados a partir da
aplica{\c{c}}{\~a}o sequencial das t{\'e}cnicas Minimum Noise
Fraction (MNF)e Pixel Purity Index (PPI). O objetivo foi
identificar para cada IV o par de bandas V-IVP que possibilitasse
o melhor contraste entre a VV e os demais componentes da cena.
Foram utilizadas larguras de bandas estreitas (10 nm)e de bandas
amplas simuladas (20 e 50 nm para o V, e 100 e 200 nm para o IVP).
Tamb{\'e}m foram simuladas as bandas dos sensores ASTER/Terra,
AVHRR/NOAA 14, MODIS/Terra, MOMS-2, MSS/Landsat 5, HRVIR/Spot 4 e
TM/Landsat 5. Finalmente, correla{\c{c}}{\~o}es entre os IVs e
os valores da fra{\c{c}}{\~a}o VV, extra{\'{\i}}dos de um
modelo linear de mistura espectral, em fun{\c{c}}{\~a}o do
posicionamento de bandas, foram obtidas e comparadas com
resultados de um experimento radioel{\'e}trico de campo feito por
Gleriani (1994). Os resultados mostram que a largura das bandas
n{\~a}o influencia o contraste espectral entre os membros de
referencia, quando s{\~a}o utilizados dados de reflect{\^a}ncia
de superf{\'{\i}}cie, desde que n{\~a}o seja invadida a
regi{\~a}o de borda vermelha (de 690 a 750 nm). Ao
contr{\'a}rio, mudan{\c{c}}as no posicionamento das bandas,
tanto do V quanto do IVP, provocam varia{\c{c}}{\~o}es no
contraste entre os alvos. O contraste e otimizado com o
posicionamento da banda do V em 677 nm, tanto para dados de
reflect{\^a}ncia de superf{\'{\i}}cie quanto aparente, e para
todos os {\'{\i}}ndices avaliados. Para a regi{\~a}o do IVP, o
NDVI apresenta otimiza{\c{c}}{\~a}o do contraste com o centro da
banda pr{\'o}ximo a 769 nm, mas o ARVI e o SAVI mostram
varia{\c{c}}{\~o}es no posicionamento das bandas de melhor
contraste, dependendo dos valores utilizados para as suas
constantes y e L. A influ{\^e}ncia da atmosfera causa
diminui{\c{c}}{\~a}o no contraste da cena, principalmente quando
a largura da banda abrange bandas de absor{\c{c}}{\~a}o
atmosf{\'e}rica no IVP. Os sensores MOMS, TM, ASTER, MODIS, HRVIR
produzem melhor contraste do que o AVHRR e o MSS. Entretanto, o
MODIS sofre menor influencia atmosf{\'e}rica, por possuir a banda
do IVP mais estreita e melhor posicionada que os demais. Embora os
resultados da correla{\c{c}}{\~a}o entre os {\'{\i}}ndices e a
fra{\c{c}}{\~a}o-VV n{\~a}o sejam inteiramente concordantes com
os do experimento radiom{\'e}trico de campo, eles revelam a
tend{\^e}ncia do par de bandas V-IVP de melhor contraste
espectral produzir tamb{\'e}m melhores estimativas dos
par{\^a}metros da vegetacao. ABSTRACT: The influences of the
positioning and width of red (R = 600-700 nm) and nearinfrared
(NIR = 750-1100 nm) bands on the determination of AVIRIS-derived
vegetation indices (Vls = NDVI, SAVI, and ARVI), as well as the
atmospheric effects, were investigated. By using the MODTRAN code,
apparent radiance AVIRIS data were converted into surface and
apparent reflectance images, respectively. The Vls were calculated
from both dataset, land for three end member spectra
representative of green vegetation (GV), nonphotosyntetic
vegetation (NPV) and soil (S). These endmember spectra were
selected from the image itself through the sequential use of the
minimum noise fraction (MNF) and pixel purity index (PPI)
techniques. The objective was to identify the best RNIR band pair
to optimize the contrast between GV and the other scene
components. Narrow (10 nm) and broad bands (R with widths of 20
and 50 {nm;} and NIR of 100 and 200 nm) were simulated in the
present investigation as well as spectral intervals equivalent to
some broadband sensors (ASTER/Terra, AVHRR/NOAA 14, MODIS/Terra,
MOMS-2, MSS/Landsat 5, HRVIR/Spot 4 and TM/Landsat 5). Finally,
correlations between Vls and fraction values of VV, derived from a
linear spectral unmixing model, were calculated and compared with
results produced with the use of a field spectroradiometric
dataset collected by Gleriani (1994). The results of the use of
surface reflectance data show that bandwidth is not an important
factor to affect spectral contrast if the R and NIR bands are not
inserted into the red edge domain (690-750 nm). On the other hand,
shifts in R-NIR band placement produce significant changes in
contrast. The best results were obtained with the R band
positioned around the chlorophyll absorption interval (677 nm),
and the NIR band placed at shorter wavelengths (769 nm). However,
the results can vary in the NIR interval for ARVI and SAVI
depending on the y and L parameters used in their calculation.
Atmospheric effects reduce the spectral contrast of the scene,
especially when the NIR bands are placed at atmospheric absorption
band intervals. From the broadband sensors investigated, MOMS, TM,
ASTER, MODIS, HRVIR produce better spectral contrasts between GV
and other scene components than AVHRR and MSS. However, if one
considers both, atmospheric effects and contrast, MODIS presents
the best results because of the positioning of its narrow NIR band
in a very convenient atmospheric window. Although there is no
complete agreement between the correlations of the Vls with the GV
fraction values (unmixing model), and with the canopy parameters
(Gleriani's experiment), the results indicate that the best R-NIR
band pair to enhance contrast tends to be also the best estimator
of the vegetation characteristics.",
committee = "Galv{\~a}o, L{\^e}nio Soares (orientador/presidente) and Novo,
Evlyn M{\'a}rcia Le{\~a}o de Moraes and Ponzoni, Fl{\'a}vio
Jorge and Epiphanio, Jos{\'e} Carlos Neves and Meneses, Paulo
Roberto",
copyholder = "SID/SCD",
englishtitle = "Influence of remote sensor band positioning and bandwidth and of
atmospheric efects on the vegetation index determinations",
label = "8840",
language = "pt",
pages = "179",
ibi = "6qtX3pFwXQZ4PKzA/o5LHo",
url = "http://urlib.net/ibi/6qtX3pFwXQZ4PKzA/o5LHo",
targetfile = "publicacao.pdf",
urlaccessdate = "2024, Dec. 11"
}