@Article{GoncalvesSantTreu:2011:StVoTr,
               author = "Goncalves, F. G and Santos, Joao Roberto dos and Treuhaft, 
                         Robert",
          affiliation = "Department of Forest Ecosystems and Society, Oregon State 
                         University, Corvallis, USA and {Instituto Nacional de Pesquisas 
                         Espaciais (INPE)} and Jet Propulsion Laboratory, California 
                         Institute of Technology, Pasadena, USA",
                title = "Stem volume of tropical forests from polarimetric radar",
              journal = "International Journal of Remote Sensing",
                 year = "2011",
               volume = "32",
               number = "2",
                pages = "503--522",
                month = "Jan.",
                 note = "Setores de Atividade: Pesquisa e desenvolvimento 
                         cient{\'{\i}}fico, Produ{\c{c}}{\~a}o Florestal.",
             keywords = "FLORESTA Nacional do Tapajos (Brazil), PARA (Brazil : State), 
                         BRAZIL, forest inventory, SAR data, tropical forest, polarimetry, 
                         Amazonia. forest management, community forests, radar, 
                         backscattering, regression analysis.",
             abstract = "In this study, we investigated the potential of polarimetric 
                         synthetic aperture radar (PolSAR) data for the estimation of stem 
                         volume in tropical forests. We used calibrated L-band, high 
                         incidence angle data from the airborne system SAR-R99B, acquired 
                         over an experimental area in the Tapajos National Forest, Para, 
                         Brazil. To evaluate the potential of PolSAR data for this 
                         application we used regression analysis, in which first-order 
                         models were fit to predict stem volume per hectare, as determined 
                         from field measurements. Unlike previous studies in tropical 
                         forests, the set of potential explanatory variables included a 
                         series of PolSAR attributes based on phase information, in 
                         addition to power measurements. Model selection techniques based 
                         on coefficient of determination (R2) and mean square error (MSE) 
                         identified several useful subsets of explanatory variables for 
                         stem volume estimation, including backscattering coefficient in HH 
                         polarization, cross-polarized ratio, HH-VV phase difference, 
                         polarimetric coherence, and the volume scatter component of the 
                         Freeman decomposition. Evaluation of the selected models indicated 
                         that PolSAR data can be used to quantify stem volume in the study 
                         site with a root mean square error (RMSE) of about 20-29 m3 ha-1, 
                         corresponding to 8-12% of the mean stem volume. External 
                         validation using independent data showed average prediction errors 
                         of less than 14%. Saturation effects in measured versus modelled 
                         volume were not observed up to volumes of 308 m3 ha-1 (biomasses 
                         of \∼357 Mg ha-1). However, no formal assessment of 
                         saturation was possible due to limitations of the volume range of 
                         the dataset.",
                  doi = "10.1080/01431160903475217",
                  url = "http://dx.doi.org/10.1080/01431160903475217",
                 issn = "0143-1161",
                label = "lattes: 1646956319628219 2 SantosTreu:2011:StVoTr",
             language = "en",
           targetfile = "GOLCALVES STEM.pdf",
        urlaccessdate = "17 maio 2024"
}