TY  - JOUR
AU  - Burkart, Andreas
AU  - Schickling, Anke
AU  - Mateo, Maria Pilar Cendrero
AU  - Wrobel, Thomas Jan
AU  - Rossini, Micol
AU  - Cogliati, Sergio
AU  - Julitta, Tommaso
AU  - Rascher, Uwe
TI  - A Method for Uncertainty Assessment of Passive Sun-Induced Chlorophyll Fluorescence Retrieval Using an Infrared Reference Light
JO  - IEEE sensors journal
VL  - 15
IS  - 8
SN  - 1558-1748
CY  - New York, NY
PB  - IEEE
M1  - FZJ-2015-06943
SP  - 4603 - 4611
PY  - 2015
AB  - Measurements of sun-induced chlorophyll fluorescence (SIF) over plant canopies provide a proxy for plant photosynthetic capacity and are of high interest for plant research. Together with spectral reflectance, SIF has the potential to act as a noninvasive approach to quantify photosynthetic plant traits from field to air and spaceborne scales. However, SIF is a small signal contribution to the reflected sunlight and often not distinguishable from sensor noise. SIF estimation is, therefore, affected by an unquantified uncertainty, making it difficult to estimate accurately how much SIF is truly emitted from the plant. To investigate and overcome this, we designed a device based on a spectrometer covering the visible range and equipped it with an LED emitting at the wavelength of SIF. Using this as a reference and applying thorough calibrations, we present consistent evidence of the instrument's capability of SIF retrieval and accuracy estimations. The LED's intensity was measured under sunlight with 1.27 ± 0.27 mW × sr-1m-2nm-1 stable over the day. The large increase of SIF due to the Kautsky effect was measured spectrally and temporally proving the biophysical origin of the signal. We propose rigorous tests for instruments intended to measure SIF and show ways to further improve the presented methods.
LB  - PUB:(DE-HGF)16
UR  - <Go to ISI:>//WOS:000357802000053
DO  - DOI:10.1109/JSEN.2015.2422894
UR  - https://juser.fz-juelich.de/record/276578
ER  -