ACT: A leaf BRDF model taking into account the azimuthal anisotropy of monocotyledonous leaf surface

REMOTE SENSING OF ENVIRONMENT

卷:143

Article

Comar, Alexis^1,2  Baret, Frederic²  Obein, Goel⁴  Simonot, Lionel⁵  Meneveaux, Daniel⁵  Vienot, Francoise³  de Solan, Benoit^1,2 

[1] INRA, UMR EMMAH, UMT CAPTE, Avignon, France

[2] Arvalis Inst Vegetal, Paris, France

[3] Museum Natl Hist Nat, CRCC, F-75231 Paris, France

[4] Lab Commun Metrol LNE CNAM, La Plaine St Denis, France

[5] Univ Poitiers, SP2MI, Chasseneuil, France

关键词: Sorghum;    Wheat;    Leaf;    Surface roughness;    BRDF;    BRF;    Reflectance;    Conoscope;    Azimuthal anisotropy;    Optical properties;    Goniometer;    Physical model;    Refractive index;   

DOI  :  10.1016/j.rse.2013.12.006

来源: Elsevier

【 摘 要 】

Leaf reflectance of monocotyledons generally displays a strong azimuthal anisotropy due to the longitudinal orientation of the veins. The Cook and Torrance (CT) bidirectional reflectance distribution function model was adapted to account for this distinctive feature. The resulting ACT (Anisotropic Cook and Torrance) model is based on the decomposition of the roughness parameter into two perpendicular components. It is evaluated on sorghum (Sorghum halepense) and wheat (Triticum durum) leaf BRF (Bidirectional Reflectance Factor) measurements acquired using a conoscope system. Results show that the ACT model fits the measurements better than azimuthally isotropic surface models: the root mean square error computed over all the BRF measurements for both leaves decreases from approximate to 0.06 for the Lambertian model to approximate to 0.04 for the CT model and down to approximate to 0.03 for the ACT model. The adjusted value of the refraction index is plausible (n approximate to 1.32) for both leaves while the retrieved roughness values perpendicular to the veins (sorghum = 0.56; wheat = 0.46) is about two times larger than that parallel to the veins (sorghum = 0.27; wheat = 0.18). Nonetheless, the observed residual discrepancies between the ACT model simulations and the measurements may be explained mainly by the Lambertian assumption of the volume scattering. (C) 2014 Elsevier Inc. All rights reserved.

【 授权许可】

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