TY  - JOUR
AU  - Cogliati, Sergio
AU  - Celesti, Marco
AU  - Cesana, Ilaria
AU  - Miglietta, Franco
AU  - Genesio, Lorenzo
AU  - Julitta, Tommaso
AU  - Schuettemeyer, Dirk
AU  - Drusch, Matthias
AU  - Rascher, Uwe
AU  - Jurado, Pedro
AU  - Colombo, Roberto
TI  - A Spectral Fitting Algorithm to Retrieve the Fluorescence Spectrum from Canopy Radiance
JO  - Remote sensing
VL  - 11
IS  - 16
SN  - 2072-4292
CY  - Basel
PB  - MDPI
M1  - FZJ-2019-05670
SP  - 1840 -
PY  - 2019
AB  - Retrieval of Sun-Induced Chlorophyll Fluorescence (F) spectrum is one of the challenging perspectives for further advancing F studies towards a better characterization of vegetation structure and functioning. In this study, a simplified Spectral Fitting retrieval algorithm suitable for retrieving the F spectrum with a limited number of parameters is proposed (two parameters for F). The novel algorithm is developed and tested on a set of radiative transfer simulations obtained by coupling SCOPE and MODTRAN5 codes, considering different chlorophyll content, leaf area index and noise levels to produce a large variability in fluorescence and reflectance spectra. The retrieval accuracy is quantified based on several metrics derived from the F spectrum (i.e., red and far-red peaks, O2 bands and spectrally-integrated values). Further, the algorithm is employed to process experimental field spectroscopy measurements collected over different crops during a long-lasting field campaign. The reliability of the retrieval algorithm on experimental measurements is evaluated by cross-comparison with F values computed by an independent retrieval method (i.e., SFM at O2 bands). For the first time, the evolution of the F spectrum along the entire growing season for a forage crop is analyzed and three diverse F spectra are identified at different growing stages. The results show that red F is larger for young canopy; while red and far-red F have similar intensity in an intermediate stage; finally, far-red F is significantly larger for the rest of the season
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000484387600003
DO  - DOI:10.3390/rs11161840
UR  - https://juser.fz-juelich.de/record/866589
ER  -