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@ARTICLE{Siegmann:894307,
      author       = {Siegmann, Bastian and Cendrero-Mateo, Maria Pilar and
                      Cogliati, Sergio and Damm, Alexander and Gamon, John and
                      Herrera, David and Jedmowski, Christoph and Junker-Frohn,
                      Laura Verena and Kraska, Thorsten and Muller, Onno and
                      Rademske, Patrick and van der Tol, Christiaan and
                      Quiros-Vargas, Juan and Yang, Peiqi and Rascher, Uwe},
      title        = {{D}ownscaling of far-red solar-induced chlorophyll
                      fluorescence of different crops from canopy to leaf level
                      using a diurnal data set acquired by the airborne imaging
                      spectrometer {H}y{P}lant},
      journal      = {Remote sensing of environment},
      volume       = {264},
      issn         = {0034-4257},
      address      = {Amsterdam [u.a.]},
      publisher    = {Elsevier Science},
      reportid     = {FZJ-2021-03167},
      pages        = {112609},
      year         = {2021},
      abstract     = {Remote sensing-based measurements of solar-induced
                      chlorophyll fluorescence (SIF) are useful for assessing
                      plant functioning at different spatial and temporal scales.
                      SIF is the most direct measure of photosynthesis and is
                      therefore considered important to advance capacity for the
                      monitoring of gross primary production (GPP) while it has
                      also been suggested that its yield facilitates the early
                      detection of vegetation stress. However, due to the
                      influence of different confounding effects, the apparent SIF
                      signal measured at canopy level differs from the
                      fluorescence emitted at leaf level, which makes its
                      physiological interpretation challenging. One of these
                      effects is the scattering of SIF emitted from leaves on its
                      way through the canopy. The escape fraction () describes the
                      scattering of SIF within the canopy and corresponds to the
                      ratio of apparent SIF at canopy level to SIF at leaf level.
                      In the present study, the fluorescence correction vegetation
                      index (FCVI) was used to determine of far-red SIF for three
                      structurally different crops (sugar beet, winter wheat, and
                      fruit trees) from a diurnal data set recorded by the
                      airborne imaging spectrometer HyPlant. This unique data set,
                      for the first time, allowed a joint analysis of spatial and
                      temporal dynamics of structural effects and thus the
                      downscaling of far-red SIF from canopy () to leaf level ().
                      For a homogeneous crop such as winter wheat, it seems to be
                      sufficient to determine once a day to reliably scale SIF760
                      from canopy to leaf level. In contrast, for more complex
                      canopies such as fruit trees, calculating for each
                      observation time throughout the day is strongly recommended.
                      The compensation for structural effects, in combination with
                      normalizing SIF760 to remove the effect of incoming
                      radiation, further allowed the estimation of SIF emission
                      efficiency (ε) at leaf level, a parameter directly related
                      to the diurnal variations of plant photosynthetic
                      efficiency.},
      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},
      pubmed       = {34602655},
      UT           = {WOS:000688411000001},
      doi          = {10.1016/j.rse.2021.112609},
      url          = {https://juser.fz-juelich.de/record/894307},
}