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Acquisition and Modeling Analysis for the Optical Properties of Maize Leaves
Published by the American Society of Agricultural and Biological Engineers, St. Joseph, Michigan www.asabe.orgCitation: 2016 ASABE Annual International Meeting 162460435.(doi:10.13031/aim.20162460435)
Authors: XUZHOU ZHANG, HUI FANG
Keywords: BRDF; the optical properties of maize leaves; measuring device; models
Abstract. The Bidirectional Reflectance Distribution Function (BRDF) is a function of five real variables that defines how light is reflected at an optics surface. The BRDF of vegetation was particularly significant, when the biophysical and chemical composition of leaves were acquired with the optical properties of leaves and near-distance imaging technology at canopy level. Measuring the reflectance and transmittance of leaves could indirectly study the interaction between light and plant leaves‘ cells. Measurement of optical properties varied with external conditions, such as nutrient use efficiency, adaption to environmental stress, is of promising prospect.
Traditionally, BRDF measurements were taken for one specific lighting and viewing direction at a time using gonio-reflectometers. In order to shorten the time of measurement process and the experiment error, we designed a three-dimensional distribution of light equipment, which can be very good implementation in a receiving azimuth under multiple zenith angle of the reflection of light distribution function. Moreover, this device can further improve the efficiency and the accuracy of the experiment.
In this paper, we will analysis the maize leaf bidirectional reflectance distribution, in the main plane direction, we will verify that maximum reflectance value appeares in the direction of principal plane light incident side near symmetrical angle, reflectance value increases with the increase of light incident angle or not. The paper will also analyze the distribution of chlorophyll bi-exponential fit, and constructed a model based on vane component to simulation the bidirectional reflectance distribution of maize.(Download PDF) (Export to EndNotes)