Author
CORP, LAWRENCE - NASA-GSFC | |
MIDDLETON, E - NASA-GSFC | |
McMurtrey Iii, James | |
CAMPBELL, P - NASA-GSFC | |
Kim, Moon | |
CHAPPELLE, E - NASA-GSFC |
Submitted to: Intnl Conference On Geospatial Information In Agriculture And Forestry
Publication Type: Proceedings Publication Acceptance Date: 8/15/2001 Publication Date: 11/5/2001 Citation: N/A Interpretive Summary: Advancements are being made in developing fluorescence imaging systems for monitoring vegetation. The systems must be designed in such a way as to collect meaningful fluorescence emission signals from vegetation even in the presence of full ambient sunlight. Fluorescence measurements have shown a great deal of promise in the remote determination of: nutrient supply in crop canopies, differentiation of crops and trees grown under elevated O3 and UV-B, and quantifying the amount of crop residue covering soil surfaces. Current research has focused on utilizing fluorescence imaging systems from a variety of platforms to receive fluorescence information which can be related to the physiological status of plant life in both terrestrial and aquatic ecosystems. Technical Abstract: Green vegetation, when excited by specific wavelengths of light, dissipate a portion of the absorbed energy as light emissions in the form of fluorescence. The principle of fluorescence involves the absorption of a specific wavelength of light by a fluorophore followed by the dissipation of the absorbed energy by light emission of a longer wavelength within a very short (i.e. < 200 ns) period of time. Fluorescence emissions from vegetation occur throughout the ultraviolet (UV-A) to visible regions of the spectrum and have been broken down into five primary bands, namely; UV, blue, green, red, and far- red. Several investigations have demonstrated relationships between these fluorescence bands and ratios of these bands to plant health and growth condition. Fluorescence measurements have shown a great deal of promise in the remote determination of: nutrient supply in crop canopies, differentiation of crops and trees grown under elevated O3 and UV-B, and quantifying the amount of crop residue covering soil surfaces. Current research has focused on utilizing fluorescence imaging systems from a variety of platforms to receive fluorescence information and this information has been related to the physiological status of the plants in both terrestrial and aquatic ecosystems. The fluorescence imaging systems described are unique and were custom fabricated through collaborative efforts of NASA and USDA. |