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@ARTICLE{Morata:1043682,
author = {Morata, Miguel and Siegmann, Bastian and García-Soria,
José Luis and Rivera-Caicedo, Juan Pablo and Verrelst,
Jochem},
title = {{O}n the potential of principal component analysis for the
reconstruction of full-spectrum {SIF} emission and emulated
airborne-to-satellite upscaling},
journal = {Remote sensing of environment},
volume = {328},
issn = {0034-4257},
address = {Amsterdam [u.a.]},
publisher = {Elsevier Science},
reportid = {FZJ-2025-02980},
pages = {114865 -},
year = {2025},
abstract = {Solar-induced fluorescence (SIF) emitted by plants as a
byproduct of photosynthesis provides critical insightsinto
vegetation health and climate regulation. However, detecting
the weak SIF signal from small telluricoxygen absorption
features remains challenging. ESA’s upcoming Fluorescence
Explorer (FLEX) mission willretrieve full-spectrum SIF data
at 300 m spatial resolution. In the meantime, we propose an
alternativeapproach to reconstruct full-spectrum SIF from
𝑂2𝐴 and 𝑂2𝐵 bands using Principal Component
Analysis(PCA) and the Soil Canopy Observation,
Photochemistry, and Energy fluxes (SCOPE) model. Based on
100,000SCOPE simulations (640–850 nm at 1 nm resolution),
the SIF signals in the 𝑂2𝐴 (760 nm) and 𝑂2𝐵 (687
nm)bands showed high correlations with adjacent spectral
regions and the full spectrum (𝑅2 > 0.89). From thisdata,
we derived linear regression functions linking SIF at the
𝑂2𝐴 (760 nm) and 𝑂2𝐵 (687 nm) bands tothe first
two principal components (PCs), enabling inverse PCA
transformation to reconstruct full-spectrumSIF with 𝑅2 >
0.98 and RMSE < 0.12 mW m−2 nm−1 sr−1. Applying the
functions to HyPlant airborne SIFmaps (1.7 m resolution) in
northeastern Spain, and subsequent PC transformation,
successfully reconstructedfull-spectrum SIF including peaks
and total emitted flux (𝑆𝐼𝐹𝑇 𝑜𝑡) with
propagated uncertainties. To transferthis airborne
full-spectrum SIF data to the satellite scale, we then
trained an emulator with PRecursoreIperSpectrale de la
Missione Applicativa (PRISMA) Bottom of Atmosphere (BOA)
reflectance spectra as inputto produce spaceborne synthetic
full-spectral SIF maps at 30 m resolution, and resampled to
the nominal300 m FLEX resolution. Despite PRISMA’s lower
spectral resolution for SIF retrieval, the emulator
reliablyproduced full-spectrum SIF with 𝑅2 of 0.69 and
0.52 for 𝑆𝐼𝐹760 and 𝑆𝐼𝐹687 bands, enabling
FLEX-likeSIF products (e.g., peaks, 𝑆𝐼𝐹𝑇
𝑜𝑡). This reconstruction and upscaling approach
demonstrates its utility forgenerating FLEX-compatible SIF
datasets, supporting FLEX’ mission preparation and cal/val
activities.},
cin = {IBG-2},
ddc = {550},
cid = {I:(DE-Juel1)IBG-2-20101118},
pnm = {2173 - Agro-biogeosystems: controls, feedbacks and impact
(POF4-217)},
pid = {G:(DE-HGF)POF4-2173},
typ = {PUB:(DE-HGF)16},
UT = {WOS:001528106500002},
doi = {10.1016/j.rse.2025.114865},
url = {https://juser.fz-juelich.de/record/1043682},
}