@MastersThesis{TeixeiraJr:2017:AnInMu,
author = "Teixeira Junior, Jefferson Fernandes",
title = "An{\'a}lise da influ{\^e}ncia de mudan{\c{c}}as de escala de
observa{\c{c}}{\~a}o sobre a caracteriza{\c{c}}{\~a}o da
fun{\c{c}}{\~a}o de distribui{\c{c}}{\~a}o da
reflect{\^a}ncia bidirecional",
school = "Instituto Nacional de Pesquisas Espaciais (INPE)",
year = "2017",
address = "S{\~a}o Jos{\'e} dos Campos",
month = "2017-08-25",
keywords = "fun{\c{c}}{\~a}o de distribui{\c{c}}{\~a}o da
reflect{\^a}ncia bidirecional, goni{\^o}metro, textura, escala
de observa{\c{c}}{\~a}o, bidirectional reflectance distribution
function, goniometer, texture, observation scale.",
abstract = "A descri{\c{c}}{\~a}o do modo como uma superf{\'{\i}}cie
reflete a radia{\c{c}}{\~a}o, em termos direcionais, pode ser
realizada por meio da fun{\c{c}}{\~a}o de
distribui{\c{c}}{\~a}o da reflect{\^a}ncia direcional (BRDF).
Esta fun{\c{c}}{\~a}o {\'e} geralmente caracterizada com o
aux{\'{\i}}lio de goni{\^o}metros em laborat{\'o}rio e/ou
campo e utilizada na compara{\c{c}}{\~a}o de dados de sensores
remotos obtidos em diferentes n{\'{\i}}veis (como aeroembarcado
e orbital) e em diferentes geometrias de ilumina{\c{c}}{\~a}o e
observa{\c{c}}{\~a}o. Neste trabalho foram investigados os
poss{\'{\i}}veis efeitos que a BRDF pode sofrer ao ser
caracterizada em diferentes n{\'{\i}}veis de
aquisi{\c{c}}{\~a}o, os quais foram simulados pela
mudan{\c{c}}a no campo de visada (FOV) de um
espectrorradi{\^o}metro. A varia{\c{c}}{\~a}o desse
par{\^a}metro (FOV) est{\'a} relacionada {\`a} mudan{\c{c}}a
da {"}escala de observa{\c{c}}{\~a}o{"}, termo usado para
definir a rela{\c{c}}{\~a}o entre as dimens{\~o}es dos
par{\^a}metros geom{\'e}tricos envolvidos na
aquisi{\c{c}}{\~a}o de dados. Dessa forma, com o
aux{\'{\i}}lio do goni{\^o}metro do LaRaC (Laborat{\'o}rio de
Radiometria e Caracteriza{\c{c}}{\~a}o de Sensores
Eletro{\'o}pticos) do Instituto de Estudos Avan{\c{c}}ados
(IEAv), foram caracterizadas as BRDF\${'}\$s de tr{\^e}s
superf{\'{\i}}cies artificiais, de mesmo material, com
diferentes texturas (lisa, com ranhuras regulares e com ranhuras
irregulares), observadas por tr{\^e}s diferentes FOVs
(1\$^{°}\$, 8\$^{°}\$ e 25\$^{°}\$) de um
espectrorradi{\^o}metro. As BRDF\${'}\$s estimadas com os
FOV\${'}\$s de 8\$^{°}\$ e de 25\$^{°}\$ se mostraram iguais
para todas as superf{\'{\i}}cies, considerando as incertezas das
medi{\c{c}}{\~o}es. Por outro lado, a BRDF estimada com FOV de
1\$^{°}\$ se mostrou igual {\`a}s estimadas com os outros
FOV\${'}\$s apenas para o caso da superf{\'{\i}}cie lisa,
enquanto para as demais superf{\'{\i}}cies apresentou
diferen{\c{c}}as quanto {\`a} intensidade (superf{\'{\i}}cie
com ranhuras regulares) e quanto {\`a} forma (superf{\'{\i}}cie
de ranhuras irregulares). Deste modo, foi poss{\'{\i}}vel
concluir que a BRDF de uma superf{\'{\i}}cie pode variar com a
escala de observa{\c{c}}{\~a}o. Assim, o presente trabalho
exp{\~o}e a necessidade de se investigar a premissa de que a BRDF
{\'e} a mesma ao se comparar dados de uma superf{\'{\i}}cie
adquiridos em diferentes n{\'{\i}}veis. ABSTRACT: The
description of how a surface reflects the radiation in directional
terms can be performed by the Bidirectional Reflectance
Distribution Function (BRDF). This function is generally
characterized using goniometers at laboratory and/or at field
level and it has been used comparing remote sensing data obtained
at different levels (such as airborne and orbital) and at
different illumination and viewing geometries. This work
investigated the possible effects that BRDF can suffer being
characterized at different acquisition levels, which were
simulated by changing the field of view (FOV) of a
spectroradiometer. The variation of FOV was related to the
{"}observation scale{"} changes, term used to define the
relationship between the dimensions of the geometric parameters
involved in data acquisition. Thus, the BRDF of three artificial
surfaces made by the same material but presenting different
superficial textures were spectrally characterized using a
goniometer developed by the Laboratory of Radiometry and
Characterization of Electro-optical Sensors (LaRaC) of the
Instituto de Estudos Avan{\c{c}}ados (IEAv). Three different FOVs
(1 \$^{°}\$, 8 \$^{°}\$ and 25 \$^{°}\$) were used for the
BRDF characterization with a spectroradiometer to simulate
observation scales. The BRDF estimated with 8 \$^{°}\$ and 25
\$^{°}\$ FOVs were similar for all surfaces, considering the
measurement uncertainties. On the other hand, the BRDF estimated
with 1 \$^{°}\$ FOV was similar to those estimated by both 8
\$^{°}\$ and 25 \$^{°}\$ only for the flat surface, while for
the other surfaces there were differences in intensity (regular
texture surface) and in shape (irregular texture surface). It was
possible to conclude that the surface BRDF can vary with the
observation scale. Thus, the present work exposed the need to
investigate the premise that the BRDF maintains the same when
comparing surface data acquired at different levels.",
committee = "Sanches, Ieda Del'Arco (presidente) and Ponzoni, Fl{\'a}vio Jorge
(orientador) and Castro, Ruy Morgado de (orientador) and Moraes,
Elisabete Caria and Moreira, Romero da Costa",
englishtitle = "Changes on data collection scale influencing the bidirectional
reflectance distribution function",
language = "pt",
pages = "116",
ibi = "8JMKD3MGP3W34P/3PQ65N5",
url = "http://urlib.net/ibi/8JMKD3MGP3W34P/3PQ65N5",
targetfile = "publicacao.pdf",
urlaccessdate = "27 abr. 2024"
}