@MastersThesis{Madruga:1997:DiReDe,
author = "Madruga, Jaqueline Leal",
title = "Diferen{\c{c}}as relativas no desempenho de algor{\'{\i}}tmos
de corre{\c{c}}{\~a}o atmosf{\'e}rica e bio-{\'o}pticos para o
processamento de imagens CZCS no Oceano Atl{\^a}ntico Sudoeste",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "1997",
address = "Sao Jose dos Campos",
month = "1997-02-26",
keywords = "oceanografia, Oceano Atl{\^a}ntico, calibra{\c{c}}{\~a}o,
algoritmos, correla{\c{c}}{\~a}o, fitoplancton,
corre{\c{c}}{\~a}o atmosf{\'e}rica, sat{\'e}lite NIMBUS,
imageador da cor de zona costeira, calibration, oceanography,
algorithms, CZCS.",
abstract = "Existem na literatura v{\'a}rios algor{\'{\i}}tmos para
obten{\c{c}}{\~a}o de estimativas de concentra{\c{c}}{\~a}o de
pigmentos no oceano a partir de imagens orbitais. Estes
algor{\'{\i}}tmos visam a remo{\c{c}}{\~a}o de efeitos
atmosf{\'e}ricos e ao c{\'a}lculo da concentra{\c{c}}{\~a}o de
pigmento. Neste trabalho s{\~a}o descritos e comparados dois
algor{\'{\i}}tmos de corre{\c{c}}{\~a}o atmosf{\'e}rica para
dez imagens CZCS; o algor{\'{\i}}tmo interativo do Smith e
Wilson (1981) (S), o qual utiliza o modelo de espalhamento simples
e o de Gordon et al. (1988) (G) que utiliza o modelo de
espalhamento m{\'u}ltiplo. Para a estimativa da
concentra{\c{c}}{\~a}o de pigmento foram usados o
algor{\'{\i}}tmo padr{\~a}o de dois canais de Gordon et al.
(1983) (P1) e um de tr{\^e}s canais de Dennis Clark
(Muller-Karger et al., 1990) (P2). Devido a aus{\^e}ncia de dados
in situ simult{\^a}neos a passagem do sat{\'e}lite, o objetivo
do trabalho restringiu-se {\`a} compara{\c{c}}{\~a}o entre os
resultados quando combinados os diferentes algor{\'{\i}}tmos.
Al{\'e}m disso foram realizadas compara{\c{c}}{\~o}es entre
dados orbitais e dados hist{\'o}ricos in situ. Concluiu-se que
para {\'a}guas profundas n{\~a}o ocorrem varia{\c{c}}{\~o}es
consider{\'a}veis ao se alterar as combina{\c{c}}{\~o}es de
algor{\'{\i}}tmos. J{\'a} para {\'a}guas de plataforma
continental as discrep{\^a}ncias entre os resultados s{\~a}o
bastante acentuadas, principalmente para concentra{\c{c}}{\~o}es
superiores a 1,0 mg/m3 , onde os valores podem ser
question{\'a}veis em fun{\c{c}}{\~a}o da grande quantidade de
material em suspens{\~a}o. Os resultados sugerem que, para as
imagens completas, os distintos algor{\'{\i}}tmos
bio-{\'o}pticos apresentam maior impacto na
determina{\c{c}}{\~a}o das concentra{\c{c}}{\~o}es de pigmento
do que os algor{\'{\i}}tmos de corre{\c{c}}{\~a}o
atmosf{\'e}rica, visto que o algor{\'{\i}}tmo de Dennis Clark
superestima os valores apresentados pelo algor{\'{\i}}tmo de
Gordon et al. (1983), independente da corre{\c{c}}{\~a}o
atmosf{\'e}rica utilizada. As estimativas de
distribui{\c{c}}{\~a}o espacial de pigmentos no Oceano
Atl{\^a}ntico Sudoeste adjacente {\`a} costa brasileira,
apresentadas pela primeira vez no presente trabalho, dever{\~a}o
ser aperfei{\c{c}}oadas atrav{\'e}s de projeto de
calibra{\c{c}}{\~a}o de novos dados orbitais com dados coletados
in situ. ABSTRACT: Orbital images have been used to estimate ocean
pigment concentration through image analysis using different
computational algorithms. These algorithms remove anomalous
effects from atmosphere and calculate the ocean pigment
concentration. Two algorithms were used to correct atmospheric
effects for ten images: the interactive algorithm based on a
simple scattering model of Smith and Wilson (1981) (S) and an
algorithm created by Gordon et al. (1988) (G), which considers the
multiple scattering model. The pigment estimates were made
considering two bio-optical algorithms: the standard two channel
algorithm from Gordon et al. (1983) (P1) and the three channel
algorithm elaborated by Dennis Clark (P2) (M{\"u}ller-Karger et
al.,1990). The objective of the present study was to compare the
results obtained from four algorithm's combinations (8P1, 8-P2,
G-P1, G-P2), since there was not in situ data available at the
same time of the satellite imagery. Orbital and historical in situ
data were also compared. It was possible to observe that for deep
ocean waters there was little variation among the algorithm' s
combinations. However, for continental shelf waters this
variations were more pronounced, mainly for concentrations above
1,0 mg/m3, such values can be questioned due to the great amount
of suspended material. For the whole set of images, the results
suggest that the bio-optical algorithms have a strong impact on
the pigment concentration determination, since the Dennis Clark
algorithm has always produced higher concentration values than the
one from Gordon et al. (1983), independently of the applied
atmospheric correction algorithms. The estimations of spatial
pigment distribution in Southwestern Atlantic Ocean adjacent to
the Brazilian coast showed for the first time in this paper,
should be improved by calibration of new orbital data set as well
as in situ data.",
committee = "Vianna, Marcio Luiz (presidente/orientador) and Garcia, Carlos
Alberto Eiras (orientador) and Lorenzetti, Jo{\~a}o Ant{\^o}nio
and Novo, Evlyn Marcia Le{\~a}o de Moraes and Galv{\~a}o,
S{\^o}nia Maria Flores Gianesella",
copyholder = "SID/SCD",
englishtitle = "Relative differences in the atmosfepheric correction and
bio-optical algorithm performace for CZCS image processing in the
Southwestern Atlantic Ocean",
label = "7720",
language = "pt",
pages = "166",
ibi = "6qtX3pFwXQZ3r59YD6/GPf8r",
url = "http://urlib.net/ibi/6qtX3pFwXQZ3r59YD6/GPf8r",
targetfile = "publicacao.pdf",
urlaccessdate = "2024, Apr. 29"
}