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@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/rep/8JMKD3MGP3W34P/3PQ65N5",
           targetfile = "publicacao.pdf",
        urlaccessdate = "24 nov. 2020"
}


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