Hyperspectral bidirectional reflectance distribution function (BRDF) data of Konza prairie grassland acquired in the First International Satellite Land Surface Climatology Project (ISLSCP) Field Experiment (FIFE) on the ground with two SE-590 instruments and remotely with the airborne advanced solid-state array spectroradiometer (ASAS) are analyzed and compared to BRDF data of dense ryegrass ob...

Various sensors have been used to obtain the canopy spectral reflectance for monitoring above-ground plant nitrogen (N) uptake in winter wheat. Comparison and intercalibration of spectral reflectance and vegetation indices derived from different sensors are important for multi-sensor data fusion and utilization. In this study, the spectral reflectance and its derived vegetation indices from thr...

We study the problem of color constancy–infering from an image the spectrum of the illumination and the reflectance spectra of all the depicted surfaces. This estimation problem is underdetermined: many surface and illumination spectra can be described as a linear combination of 3 basis functions, giving 3 unknowns per pixel, plus 3 parameters for a global illumination. A trichromatic visual sy...

Metal nanoparticles can function as optical contrast enhancers for reflectance-based diagnosis of epithelial precancer. We carry out Monte Carlo simulations to model photon propagation through normal tissues, unlabeled precancerous tissues, and precancerous tissues labeled with gold nanospheres and we compute the spectral reflectance response of these different tissue states. The results indica...

Informative spectral bands for green leaf area index (LAI) estimation in two crops were identified and generic models for soybean and maize were developed and validated using spectral data taken at close range. The objective of this paper was to test developed models using Aqua and Terra MODIS, Landsat TM and ETM+, ENVISAT MERIS surface reflectance products, and simulated data of the recently-l...

The color of prints is mainly determined by the light absorption of the inks deposited on top of paper. In order to predict the reflectance spectrum of prints, we use a spectral prediction model in which each ink is characterized by its spectral transmittance. In the present paper, we consider two classical reflectance prediction models: the Clapper-Yule model and the Williams-Clapper model. Th...

Recent research in range ecology has emphasized the importance of forage quality as a key indicator of rangeland condition. However, we lack tools to evaluate forage quality at scales appropriate for management. Using canopy reflectance data to measure forage quality has been conducted at both laboratory and field levels separately, but little work has been conducted to evaluate these methods s...

©2001, IS&T—The Society for Imaging Science and Technology ject remains invariant with changes in the illumination. The mechanisms that provide color constancy must decompose the reflected light and discount the spectral properties of the illumination in order to establish the colors of the objects in terms of their surface reflectance functions.3–5 Most previous research on the reproduction of...

Integrating sphere reflectometers are used in the majority of instruments used for spectral reflectance measurements of non-specular (scattering) samples. Knowledge of directional-hemispherical spectral reflectance (and transmittance, in the case of semi-transparent samples) allows one to derive the spectral directional emittance , which is of considerable practical interest for numerous heat t...

Monitoring the components of crop canopies with remote sensing can help us understand the within-canopy variation in spectral properties and resolve the sources of uncertainties in the spectroscopic estimation of crop foliar chemistry. To date, the spectral properties of leaves and panicles in crop canopies and the shadow effects on their spectral variation remain poorly understood due to the i...