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Leaf-shape effects in electromagnetic wave scattering from vegetationA vegetation medium is modeled as a half-space of randomly distributed and oriented leaves of arbitrary shape. In accordance with the first-order radiative transfer theory, the backscattering coefficient for such a half-space is expressed in terms of the scattering amplitudes. For disc- or needle-shaped leaves, the generalized Rayleigh-Gans approximation is used to calculate the scattering amplitudes. This approach is valid for leaf dimensions up to the size of the incident wavelength. To examine the leaf-shape effect, elliptic discs are used to model deciduous leaves, and needles are used to model coniferous leaves. The differences between the scattering characteristics of leaves of different shapes are illustrated numerically for various orientations, frequencies, and incidence angles. It is found that the scattering characteristics of elliptic disc-shaped leaves are sensitive to the three angles of orientation and disc ellipticity. In general, both like and cross polarizations may be needed to differentiate the difference in scattering due to the shapes of the leaves.
Document ID
19900030794
Acquisition Source
Legacy CDMS
Document Type
Reprint (Version printed in journal)
Authors
Karam, Mostafa A.
(Texas Univ. Arlington, TX, United States)
Fung, Adrian K.
(Texas, University Arlington, United States)
Date Acquired
August 14, 2013
Publication Date
November 1, 1989
Publication Information
Publication: IEEE Transactions on Geoscience and Remote Sensing
Volume: 27
ISSN: 0196-2892
Subject Category
Earth Resources And Remote Sensing
Accession Number
90A17849
Funding Number(s)
CONTRACT_GRANT: NAG5-486
Distribution Limits
Public
Copyright
Other

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