Analyses of Impact of Needle Surface Properties on Estimation of Needle Absorption Spectrum: Case Study with Coniferous Needle and Shoot Samples

Bin Yang, Yuri Knyazikhin, Yi Lin, Kai Yan, Chi Chen, Taejin Park, Sungho Choi, Matti Mottus, Miina Rautiainen, Ranga B. Myneni, Lei Yan*

*Corresponding author for this work

Research output: Contribution to journalArticleScientificpeer-review

21 Citations (Scopus)
369 Downloads (Pure)

Abstract

Leaf scattering spectrum is the key optical variable that conveys information about leaf absorbing constituents from remote sensing. It cannot be directly measured from space because the radiation scattered from leaves is affected by the 3D canopy structure. In addition, some radiation is specularly reflected at the surface of leaves. This portion of reflected radiation is partly polarized, does not interact with pigments inside the leaf and therefore contains no information about its interior. Very little empirical data are available on the spectral and angular scattering properties of leaf surfaces. Whereas canopy-structure effects are well understood, the impact of the leaf surface reflectance on estimation of leaf absorption spectra remains uncertain. This paper presents empirical and theoretical analyses of angular, spectral, and polarimetric measurements of light reflected by needles and shoots of Pinus koraiensis and Picea koraiensis species. Our results suggest that ignoring the leaf surface reflected radiation can result in an inaccurate estimation of the leaf absorption spectrum. Polarization measurements may be useful to account for leaf surface effects because radiation reflected from the leaf surface is partly polarized, whereas that from the leaf interior is not.

Original languageEnglish
Article number563
Number of pages17
JournalRemote Sensing
Volume8
Issue number7
DOIs
Publication statusPublished - Jul 2016
MoE publication typeA1 Journal article-refereed

Keywords

  • leaf albedo
  • leaf biochemistry
  • leaf surface reflectance
  • polarization measurements
  • OPTICAL-PROPERTIES
  • LEAF REFLECTANCE
  • CANOPY
  • MODEL
  • VEGETATION
  • NITROGEN
  • DIFFERENTIATION
  • INVARIANTS
  • DIFFUSE

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