Journal Article

FZJ-2025-02980

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png On the potential of principal component analysis for the reconstruction of full-spectrum SIF emission and emulated airborne-to-satellite upscaling

Morata, M. (Corresponding author) ; Siegmann, B.FZJ* ; García-Soria, J. L. ; Rivera-Caicedo, J. P. ; Verrelst, J.

2025
Elsevier Science Amsterdam [u.a.]

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Please use a persistent id in citations: doi:10.1016/j.rse.2025.114865  doi:10.34734/FZJ-2025-02980

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.

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Contributing Institute(s):

1. Pflanzenwissenschaften (IBG-2)

Research Program(s):

1. 2173 - Agro-biogeosystems: controls, feedbacks and impact (POF4-217) (POF4-217)

Appears in the scientific report 2025

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Database coverage:
; ; ; BIOSIS Previews ; Biological Abstracts ; Clarivate Analytics Master Journal List ; Current Contents - Physical, Chemical and Earth Sciences ; Ebsco Academic Search ; Essential Science Indicators ; IF >= 10 ; JCR ; Nationallizenz ; SCOPUS ; Science Citation Index Expanded ; Web of Science Core Collection

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