Monitoring canopy chemistry with HyspIRI and other planned imaging spectrometers

摘要

A significant literature has developed over the past 20 years that demonstrates that imaging spectroscopy can quantify concentrations of plant pigments, water, nitrogen, and structural carbohydrates (cell wall material and other dry matter in plants, e.g., cellulose and lignin) based on physical principles of spectroscopy rather than empirical relationships that are derived using multiband data. Several governments have announced plans to launch imaging spectrometers over the next few years. With exception of NASA's planned HyspIRI mission (http://hyspiri.jpl.nasa.gov/), all will be sampling missions, limited to a few acquisitions per day and some will only measure the visible to near-infrared region and not the full solar spectrum through the shortwave-infrared. The availability of these data will facilitate far greater understanding of biogeochemical cycles, species distributions, and monitoring the health of the ecosystem.