685nm 
Without 
DCMU 
With 
DCMU 
Fig. 9. Processed multi-colour 
fluorescence images of a maize 
plant displaying the fluorescence 
ratio I(685nm)/I(bluei The 
upper image is the same as the 
processed image in Fis. S and 
the lower image is recorded half 
an hour later after application of 
the herbicide DCMU. 
remotely measured spectra have a 
very good signal-to-noise ratio even for single-shot recordings. The measurements performed with the 
imaging system show that particularly the divided image, where influences of distance and non-uniform 
laser intensity are eliminated, can be used to see differences in the vegetation which occur due to different 
environmental parameters. 
5. ACKNOWLEDGEMENTS 
This work w'as supported by the Swedish Natural Science Research Council and the Swedish Space Board.