ABSTRACT
Exploitation of the distinctive spectral signature of living vegetation in the visible and near-infrared wavebands has allowed great advances to be made in applying remote sensing techniques to agricultural and ecological monitoring. Applications include the routine monitoring of crops to predict their economic yields, regional early warning systems for famine or pest infestation and phenological mapping of natural vegetation. Many of these successes are based on relating spectral indices of vegetation to the fraction of photosynthetically active radiation (or light) absorbed by the canopy, allowing vegetation indices to be used as direct measures of primary productivity.
