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Title: Modeling the directional reflectance from complete homogeneous vegetation canopies with various leaf-orientation distributions

Journal Article · · J. Opt. Soc. Am. A; (United States)

The directional-reflectance distributions of radiant flux from homogeneous vegetation canopies with greater than 90% ground cover are analyzed with a radiative-transfer model. The model assumes that the leaves consist of small finite planes with Lambertian properties. Four theoretical canopies with different leaf-orientataion distributions were studied: erectophile, spherical, planophile, and heliotropic canopies. The directional-reflectance distributions from the model closely resemble reflectance distributions measured in the field. The physical scattering mechanisms operating in the model explain the variations observed in the reflectance distributions as a function of leaf-orientation distribution, solar zenith angle, and leaf transmittance and reflectance. The simulated reflectance distributions show unique charateristics for each canopy. The basic understanding of the physical scattering properties of the different canopy geometries gained in this study provide a basis for developing techniques to infer leaf-orientation distributions of vegetation canopies from directional remote-sensing measurements.

Research Organization:
NASA Goddard Space Flight Center, Earth Resources Branch, Code 923, Greenbelt, Maryland 20771
OSTI ID:
5991016
Journal Information:
J. Opt. Soc. Am. A; (United States), Vol. 1:7
Country of Publication:
United States
Language:
English