A polarization photometer has been developed for rapidly determining the bidirectional, polarized, and diffuse light-scattering properties of individual leaves illuminated and measured in vivo at an angle of 55° (approximately Brewster's angle) in six wavelength bands in the visible and near-infrared wavelength regions. The optical performance and data quality of the system are evaluated to estimate the magnitude of the variation in the data attributable to the instrument system and to measurement procedures. The potential to discriminate between three species of oak is demonstrated using data acquired by the polarization photometer. The instrument is being used to increase understanding of the radiation transfer process in plant canopies and specifically to determine how agronomic information of the physical and chemical processes in leaves, plants, and plant canopies is expressed in these light-scattering properties.
V. C. Vanderbilt,
"Polarization Photometer To Measure Bidirectional Reflectance Factor R(55°, 0°; 55°,180°) Of Leaves," Optical Engineering 25(4), 254566 (1 April 1986). https://doi.org/10.1117/12.7973861