@InProceedings{PerrottaJuSoSeAlOl:2013:DaBiEs,
               author = "Perrotta, M{\^o}nica Mazzini and Justo, Ana Paula and Souza 
                         Filho, Carlos Roberto de and Senna, Juliano Alves de and Almeida, 
                         Tales Am{\'e}rico Sp{\'{\i}}nola de and Oliveira, Sergio 
                         Azevedo Marques de",
                title = "Estudo de assinaturas espectrais de metavulc{\^a}nicas do 
                         Espinha{\c{c}}o Setentrional e sua aplica{\c{c}}{\~a}o no 
                         mapeamento mineral em imagem do sensor ASTER: dados da Biblioteca 
                         Espectral do Servi{\c{c}}o Geol{\'o}gico do Brasil",
            booktitle = "Anais...",
                 year = "2013",
               editor = "Epiphanio, Jos{\'e} Carlos Neves and Galv{\~a}o, L{\^e}nio 
                         Soares",
                pages = "3656--3663",
         organization = "Simp{\'o}sio Brasileiro de Sensoriamento Remoto, 16. (SBSR)",
            publisher = "Instituto Nacional de Pesquisas Espaciais (INPE)",
              address = "S{\~a}o Jos{\'e} dos Campos",
             abstract = "A set of spectral signatures of the Northern Espinha{\c{c}}o 
                         Supergroup (NES) metavolcanic rocks were acquired and assigned to 
                         the newly built Geological Survey of Brazil (GSB) Spectral 
                         Library. This database comprises VNIR-SWIR (350 to 2500 nm) 
                         spectra of fresh and altered rock samples measured with an ASD 
                         FieldSpec-3 High-Resolution spectroradiometer. The identification 
                         of minerals in mixed spectra was performed using the SIMIS Feature 
                         Searchİ software wich allows discrimination of mineral phases by 
                         comparing the absorption features of unknown minerals with similar 
                         features of minerals listed in a reference spectral library. 
                         Whereas spectral signatures related to compositional variations in 
                         fresh rocks proved difficult to distinguish, in altered samples it 
                         was possible to identify a number of individual minerals and 
                         assemblages, including sericite/muscovite, illite, kaolinite, 
                         montmorillonite, goethite, hematite, dickite or pyrophyllite, 
                         calcite, chlorite and barite. These mineral assemblages are 
                         consistent with epithermal hydrothermal alteration previously 
                         described assemblages in NES altered volcanics. 
                         Atmospherically-compensated ASTERs multispectral data were used to 
                         map the distribution of hydrothermal alteration minerals based on 
                         endmembers selected from the NES spectral library. Spectral Angle 
                         Mapper (SAM) and Mixture Tuned Matched Filtering (MTMF) were the 
                         algorithms employed for the task. Both mapping methods were able 
                         to recognize pixels in the imagery similar to the endmembers. 
                         Reference spectra and spectra extracted from ASTER imagery pixels 
                         also proved to match at equivalent sites in the field, 
                         particularly in the SAM-derived maps. These results strengthen the 
                         potential use of the GSB Spectral Library of rocks to assist in 
                         geologic mapping and mineral exploration campaigns.",
  conference-location = "Foz do Igua{\c{c}}u",
      conference-year = "13-18 abr. 2013",
                 isbn = "{978-85-17-00066-9 (Internet)} and {978-85-17-00065-2 (DVD)}",
                label = "1334",
             language = "pt",
         organisation = "Instituto Nacional de Pesquisas Espaciais (INPE)",
                  ibi = "3ERPFQRTRW34M/3E7GKHK",
                  url = "http://urlib.net/ibi/3ERPFQRTRW34M/3E7GKHK",
           targetfile = "p1334.pdf",
                 type = "Geologia",
        urlaccessdate = "16 jun. 2024"
}