Natural Resources, School of

 

Date of this Version

2001

Comments

Published in Gitelson, Merzlyak, Zur, Stark & Gritz in the Proceedings of the 3rd European Conference on Precision Agriculture, Montpelier, France, 2001. Grenier & Blackmore, editors.

Abstract

The goal of this work is to develop non-destructive techniques that can conveniently, rapidly and accurately assess crop physiological status and objectively evaluate plant responses to environmental factors, both natural and anthropogenic. High spectral resolution reflectance and absorption spectra of different and unrelated plant species were analyzed to determine spectral variability and information content in the visible and near-infrared spectrum at leaf and canopy levels. Techniques were developed to quantitatively retrieve chlorophyll, carotenoid and anthocyanin content from reflectance in a wide range of pigment content and composition.

Techniques for vegetation fraction retrieval those based on channels in visible range of the spectrum were developed and validated. Despite the fact that the reflectance contrast among the visible channels is much smaller than between the visible and near infrared, the sensitivity to moderate to high values of vegetation fraction is much higher than for NDVI and the error in vegetation fraction prediction did not exceed 10 per cent.