@MastersThesis{Morelli:1993:InGeVi,
author = "Morelli, Ademir Fernando",
title = "Influ{\^e}ncia da geometria de visada na reflect{\^a}ncia
espectral de duas gram{\'{\i}}neas forregeiras",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "1993",
address = "Sao Jose dos Campos",
month = "1993-02-26",
keywords = "agronomia, reflectancia espectral, geometria de visada, spectral
reflectance.",
abstract = "Est{\'a} faltando a p{\'a}gina 191 no arquivo digital do
trabalho. A pesquisa teve como objetivo a avalia{\c{c}}{\~a}o da
influencia da varia{\c{c}}{\~a}o da geometria de visada no
comportamento espectral da vegeta{\c{c}}{\~a}o herb{\'a}cea e
do substrato subjacente em pastagens compostas por Brachiaria
decumbens Stapf. cv. Basilik e Brachiaria brizantha Stapf. cv.
Marandu. O desenvolvimento metodol{\'o}gico envolveu a
an{\'a}lise da rela{\c{c}}{\~a}o entre a reflect{\^a}ncia
espectral e os par{\^a}metros biof{\'{\i}}sicos da
vegeta{\c{c}}{\~a}o herb{\'a}cea e do substrato subjacente.
Para tanto, foram realizadas medi{\c{c}}{\~o}es
radiom{\'e}tricas e biof{\'{\i}}sicas para 25 amostras da
vegeta{\c{c}}{\~a}o e para uma amostra do solo em {\'a}reas
experimentais de 1000m2, para cada esp{\'e}cie. As medidas de
reflect{\^a}ncia bidirecional multiespectral (500 a 1100 nm)
foram obtidas nos {\^a}ngulos zenitais de 0, 15, 30, 45 e 60
graus para 3 setores do plano azimutal (0,90 e 180 graus), com a
varia{\c{c}}{\~a}o do {\^a}ngulo zenital solar controlada para
uma amplitude de 10 graus (45º -55º) e a varia{\c{c}}{\~a}o
azimutal solar compensada no m{\'e}todo de aquisi{\c{c}}{\~a}o.
Foram avaliados os seguintes par{\^a}metros biom{\'e}tricos da
vegeta{\c{c}}{\~a}o: fitomassa total fresca e seca, fitomassa
verde fresca e seca, fitomassa seca fresca e seca, teor de agua
total e da fitomassa verde e seca, folhas verdes e secas, colmos
verdes e secos, {\'{\i}}ndice de {\'a}rea foliar, {\'a}rea
foliar total, {\'{\i}}ndice de cobertura,
distribui{\c{c}}{\~a}o angular das folhas estratificada por
altura da cobertura e altura da cobertura. Os par{\^a}metros do
solo analisados foram a classifica{\c{c}}{\~a}o da cor do solo
segundo a tabela Munsell, teor de mat{\'e}ria org{\^a}nica,
textura e rugosidade. Tal desenvolvimento visa a compreens{\~a}o,
em n{\'{\i}}vel quantitativo, dos principais mecanismos
f{\'{\i}}sicos envolvidos na din{\^a}mica da reflect{\^a}ncia
bidirecional multiespectral de coberturas vegetais homog{\^e}neas
e suas influ{\^e}ncias na rela{\c{c}}{\~a}o entre os
indicadores espectrais e os par{\^a}metros biof{\'{\i}}sicos. O
comportamento geral verificado foi coerente com o observado na
literatura para coberturas completas de gram{\'{\i}}neas, sendo
explicado pela atua{\c{c}}{\~a}o conjunta dos mecanismos
f{\'{\i}}sicos conhecidos como {{{{"}efeito}}} {{1\{"}}}
(efeito geom{\'e}trico da estrutura da vegeta{\c{c}}{\~a}o) e
{{{{"}fun{\c{c}}{\~a}o}}} de {{fase\{"}}} (efeito das
propriedades {\'o}pticas dos constituintes da
vegeta{\c{c}}{\~a}o). As maiores varia{\c{c}}{\~o}es nos
valores dos FRBMs (Fatores de Reflect{\^a}ncia Bidirecional
Multiespectral) ocorreram no plano azimutal paralelo ao plano
solar, enquanto as menores ocorreram no plano perpendicular ao
solar. As bandas no vis{\'{\i}}vel foram as mais influenciadas
pela varia{\c{c}}{\~a}o da geometria de visada, apresentando
varia{\c{c}}{\~o}es azimutais e zenitais superiores as
observadas para as bandas no IVP. Para as duas coberturas n{\~a}o
se verificou uma influencia significativa do espalhamento
anisotr{\'o}pico do solo na distribui{\c{c}}{\~a}o angular dos
FRBMs. O m{\'a}ximo conte{\'u}do de informa{\c{c}}{\~a}o sobre
a estrutura geom{\'e}trica da cobertura esta no AAV de 180º, que
melhor se correlacionou com os par{\^a}metros
biof{\'{\i}}sicos, devido a ocorr{\^e}ncia dos picos
prim{\'a}rio e secund{\'a}rio de reflex{\~a}o. As piores
correla{\c{c}}{\~o}es ocorreram no AAV de 0º e est{\~a}o
relacionadas ao comportamento inverso da reflect{\^a}ncia
(diminui{\c{c}}{\~a}o) com o aumento do AZV. Os maiores
coeficientes de correlacao ocorridos com a maioria dos
par{\^a}metros biof{\'{\i}}sicos no AZV de 45º est{\~a}o
associados a ocorr{\^e}ncia dos picos prim{\'a}rio e
secund{\'a}rio de reflex{\~a}o pr{\'o}ximos a esse AZV. Os
par{\^a}metros caracterizadores da produ{\c{c}}{\~a}o e do teor
de agua apresentaram as melhores correla{\c{c}}{\~o}es,
principalmente por estarem mais relacionados a faixa do IVP, que
apresentou as maiores correla{\c{c}}{\~o}es. O efeito
geom{\'e}trico da cobertura foi o mecanismo dominante, mas teve
seus efeitos alterados pela atua{\c{c}}{\~a}o do efeito da
fun{\c{c}}{\~a}o de fase. ABSTRACT: The objective of this
research was to evaluate the influence's valuation of view
geometry variation in spectral behaviour of herbaceous vegetation
and sou l underlying in composition pastures for Brachiaria
decumbens Stapf. cv. Basilik Stapf and Brachiaria brizantha Stapf.
cv. Marandu. The metodology development involved the report
analysis between the spectral reflectance and the biophysics
parameters of herbaceous vegetation and sou. For this purpose
radiometric and biophysics measurements were done for 25
vegetation samples and one soil sample, in experiment areas of
1000 m2, for each species. The multispectral bidirectional
reflectance measurements (500 to 1100 nm) were obtained in the
view zenith angles {{{(\θv)}}} of 0º, 15º, 30º, 45º and 60º
for three sectors of azimutal plain {{{(\Φv}}} = Oº, 90º and
180º), with the solar zenith angle variation controlled for an
amplitude of the 10º {{{(\θs}}} = 45º to 55º) and the solar
azimutal variation compensated ia the acquisition method. The
following vegetation parameters were measured: fresh and dry
biomass, fresh and dry green biomass, droughty biomass and leaf
and {{{stems;}}} water content of total, green and droughtry
biomassa, Leaf Area Index (LAI) and percentage of canopy cover.
The sou parameters available were color, roughness and chemistry
composition. This research intent is the comprehension of physical
mechanisms involved in the directional reflectance factor
distribution of complete homogeneous vegetation canopies and lis
influences in the relation between spectral behavior and
vegetation parameters. 'The general scattering behavior was
coherent with the dinamics observed in the literature and was
supported by phenomena of the {{{{"}phase}}} {{function\{"}}} and
{{{{"}geometric}}} effect {{1\{"}.}} The major trends observed ia
the reflectance factor ocurred in the azimuth in the principal
plane of the sun {{{(\Φs}}} = 0º and 180º), while the minor
trends ocurred in the azimuth direction perpendicular to the
principal plane of the sun {{{(\Φv}}} = 90º). For ali view
angles and spectral bands the minimum reflectance ocurred near
nadir {{{(\θv}}} = 0º) and increased with increasing view
zenith angles for ali azimuth directions. This trend is caused by
the shading of lower canopy layers, by components in the upper
layers and by viewing different proportions of the layer
components as the view angle changes {{(\{"}effect}} {{I\{"}).}}
In some cases by an adtive effect of {{{{"}phase}}}
{{function\{"}}} (depending of optical properties of plant
components), the reflectance minimum was shifted slighfiy
off-nadir in the foward scattering direction {{{(\Φs}}} =
0º). This shift was maximized for -ocurrence of reproductive
structures in the top layers of cover, becau,se this stnicture is
vertical and pague. The near infrared band was less influenced by
view geometry variation than in the spectral bands of visible,
because in the near infrared bancl the transmittance was nearly
equal to the reflectance for most structural components of
herbaceous vegetation, while in the visible the reflectance is
major, consequently the {{{{"}effect}}} {{1\{"}}} is maximized.
The major information content about vegetation cover was obtained
in the principal plane of the sun, in the hackscattering direction
{{{\Φ}}} =180º), than showed better relationships to the
vegetation parameters, because of the ocurrence of {{{{"}hot}}}
{{spot\{"}.}} The vegetation parameters of prodution and water
content showed the best correlations, because its parameters have
more association to the near infrared, that exhibited the better
performance than visible bands, more associated to LAI and fresh
and dry biomass components. The {{{{"}effect}}} {{1\{"}}} was the
dominant phenomenon that controlled the directional reflectance
distributions observed, but had its effects alterated by the
action of additional phenomenon {{{{"}phase}}}
{{function\{"}.}.}",
committee = "Formaggio, Antonio Roberto (presidente/orientador) and Epiphanio,
Jos{\'e} Carlos Neves (orientador) and Soares, Jo{\~a}o Vianei
and Louren{\c{c}}o, Antonio Jo{\~a}o",
copyholder = "SID/SCD",
englishtitle = "The influence of view geometry variation in spectral reflectance
of two forage grasses",
label = "7499",
language = "pt",
pages = "224",
ibi = "6qtX3pFwXQZ3r59YD6/GP6L6",
url = "http://urlib.net/ibi/6qtX3pFwXQZ3r59YD6/GP6L6",
targetfile = "publicacao_faltando p{\'a}gina 191.pdf",
urlaccessdate = "28 abr. 2024"
}