@Article{FerreiraFéGrGaShSo:2018:ReStCh,
author = "Ferreira, Matheus Pinheiro and F{\'e}ret, Jean-Baptiste and Grau,
Eloi and Gastellu-Etchegorry, Jean-Philippe and Shimabukuro, Yosio
Edemir and Souza Filho, Carlos Roberto de",
affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and
{Universit{\'e} Montpellier} and {Universit{\'e} Montpellier}
and {Centre d'Etudes Spatiales de la BIOsph{\`e}re (CESBIO)} and
{Instituto Nacional de Pesquisas Espaciais (INPE)} and
{Universidade Estadual de Campinas (UNICAMP)}",
title = "Retrieving structural and chemical properties of individual tree
crowns in a highly diverse tropical forest with 3D radiative
transfer modeling and imaging spectroscopy",
journal = "Remote Sensing of Environment",
year = "2018",
volume = "211",
pages = "276--291",
month = "June",
keywords = "Hyperspectral remote sensing, DART, Functional traits, Model
inversion, Tree species classification, Tropical forest.",
abstract = "Spatial and temporal information on the structural and chemical
properties of tropical forest canopies are key to understanding
ecosystem processes. However, such information is usually limited
to field studies performed at the plot level (~1\ ha). The
combination of imaging spectroscopy with physically based
radiative transfer (RT) models holds great promise for
generalizing and extrapolating insights from plot-based studies to
whole landscapes. Here, we tested the capacity of a simplified 3D
RT approach to retrieve the structural and chemical traits of
individual tree crowns (ITCs) from a highly diverse tropical
forest. We first produced two datasets called measured and
simulated. The measured dataset was composed of ITC reflectance
extracted from sunlit imaging spectroscopy pixels. The simulated
dataset was produced using a look-up-table approach and the
discrete anisotropic radiative transfer (DART) model. We then
compared the simulated and measured reflectances of ITCs in terms
of shape difference by computing the spectral angle. The results
showed small disagreements between the simulated and measured
reflectances. Such differences impacted neither the spectral
variability nor the spectral regions recognized as useful for
species discrimination, showing that the spectral angle was a
suitable measure of spectral similarity. Simulation robustness was
assessed by comparing model parameters obtained by inversion to
imaging spectroscopy vegetation indices and the proportion of
non-photosynthetic vegetation (NPV), green photosynthetic
vegetation (GV) and shade estimated within ITCs. DART canopy
structural parameters were related to NPV
(R2\ =\ 0.71), GV (R2\ =\ 0.78) and
shade (R2\ =\ 0.55). DART canopy foliar parameters
such as chlorophyll and carotenoids were related to the ratio of
TCARI/OSAVI (R2\ =\ 0.80) indices and the simple
ratio between reflectances at 515\ nm and 570\ nm
(R515/R570) (R2\ =\ 0.54), respectively.
Species-related differences in NPV, GV and shade were explained by
variations in crown architectural characteristics. The simulation
framework employed in this study can be applied to retrieve
structural and chemical traits of ITCs from other areas in which
high-resolution imaging spectroscopy data are available.",
doi = "10.1016/j.rse.2018.04.023",
url = "http://dx.doi.org/10.1016/j.rse.2018.04.023",
issn = "0034-4257",
language = "en",
targetfile = "ferreira_retrieving.pdf",
urlaccessdate = "27 abr. 2024"
}