@InProceedings{SilvaVibr:2017:EsPr,
               author = "Silva, Daniel Augusto da and Vibrans, Alexander Christian",
                title = "Interfer{\^e}ncia do m{\'e}todo de aquisi{\c{c}}{\~a}o e 
                         processamento de fotos hemisf{\'e}ricas na 
                         determina{\c{c}}{\~a}o do {\'{\I}}ndice de {\'A}rea Foliar: 
                         um estudo preliminar",
            booktitle = "Anais...",
                 year = "2017",
               editor = "Gherardi, Douglas Francisco Marcolino and Arag{\~a}o, Luiz 
                         Eduardo Oliveira e Cruz de",
                pages = "4406--4413",
         organization = "Simp{\'o}sio Brasileiro de Sensoriamento Remoto, 18. (SBSR)",
            publisher = "Instituto Nacional de Pesquisas Espaciais (INPE)",
              address = "S{\~a}o Jos{\'e} dos Campos",
             abstract = "The leaf area index (LAI) is an important parameter in the forest 
                         and interferes in various ecosystem processes. Its determination 
                         via hemispherical photography are cheap, operationally simple and 
                         reliable when the correct methods are applied. The LAI is obtained 
                         by the inversion of the gap fraction viewed in different zenith 
                         angles from a single point. The setting of the camera determines 
                         the level of contrast between the canopy and the sky and, thus, 
                         affect the capacity of the software to correct discern these two 
                         classes in the later classification step. Also, the utilization of 
                         automatic thresholding or supervised classification interferes 
                         greatly in the precision and replicability of the study. Three 
                         settings in the camera were tested, one automatic and two manual, 
                         and the two methods of classification, automatic and supervised. 
                         The study was run in a fragment of secondary Atlantic Forest in 
                         Santa Catarina, where 15 experimental points were randomly 
                         defined, in each point 3 photos were taken, one in each camera 
                         setting. After, the LAI were determined in two separate software, 
                         using automatic and supervised classification of the photos. There 
                         were a systematic underestimation of the LAI using the automatic 
                         setting of the camera, but the two manual setting returned similar 
                         results. The supervised classification overestimated the LAI in 
                         all camera settings. Based on these preliminary results, are 
                         recommended the utilization of manual mode for the photo 
                         acquisition and automatic threshold for the classification step. 
                         Further studies are needed to determine a better protocol for the 
                         photo acquisition.",
  conference-location = "Santos",
      conference-year = "28-31 maio 2017",
                 isbn = "978-85-17-00088-1",
                label = "59884",
             language = "pt",
         organisation = "Instituto Nacional de Pesquisas Espaciais (INPE)",
                  ibi = "8JMKD3MGP6W34M/3PSM33P",
                  url = "http://urlib.net/ibi/8JMKD3MGP6W34M/3PSM33P",
           targetfile = "59884.pdf",
                 type = "Processamento de imagens",
        urlaccessdate = "27 abr. 2024"
}