Ciencias Agrarias >
Instituto de Agricultura Sostenible (IAS) >
(IAS) Artículos >
Closed Access item Needle Chlorophyll content estimation through model inversion using hyperspectral data from Boreal Conifer Forest Canopies
|Authors:||Zarco-Tejada, Pablo J.|
Miller, J. R.
Noland, T. L.
Goel, N. S.
Mohammed, G. H.
Sampson, P. H.
|Keywords:||Chlorophyll, Canopy modelling, Needle reflectance, Hyperspectral, Optical indices, Radiative transfer|
|Citation:||Remote Sensing of Environment, 89(2), 189-199|
|Abstract:||Leaf chlorophyll content in coniferous forest canopies, a measure of stand condition, is the target of studies and models linking leaf
reflectance and transmittance and canopy hyperspectral reflectance imagery. The viability of estimation of needle chlorophyll content from
airborne hyperspectral optical data through inversion of linked leaf level and canopy level radiative transfer models is discussed in this paper.
This study is focused on five sites of Jack Pine (Pinus banksiana Lamb.) in the Algoma Region (Canada), where field, laboratory and
airborne data were collected in 1998 and 1999 campaigns. Airborne hyperspectral CASI data of 72 bands in the visible and near-infrared
region and 2 m spatial resolution were collected from 20 20 m study sites of Jack Pine in 2 consecutive years. It was found that needle
chlorophyll content could be estimated at the leaf level (r2 = 0.4) by inversion of the PROSPECT leaf model from needle reflectance and
transmittance spectra collected with a special needle carrier apparatus coupled to the Li-Cor 1800 integrating sphere. The Jack Pine forest
stands used for this study with LAI > 2, and the high spatial resolution hyperspectral reflectance collected, allowed the use of the SPRINT
canopy reflectance model coupled to PROSPECT for needle chlorophyll content estimation by model inversion. The optical index R750/
R710 was used as the merit function in the numerical inversion to minimize the effect of shadows and LAI variation in the mean canopy
reflectance from the 20 20 m plots. Estimates of needle pigment content from airborne hyperspectral reflectance using this linked leafcanopy
model inversion methodology showed an r2 = 0.4 and RMSE = 8.1 Ag/cm2 when targeting sunlit crown pixels in Jack Pine sites with
pigment content ranging between 26.8 and 56.8 Ag/cm2 (1570–3320 Ag/g).|
|Publisher version (URL):||http://dx.doi.org/10.1016/j.rse.2002.06.002|
|Appears in Collections:||(IAS) Artículos|
Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.