Hr 
* * * + : 
t s] MN 
Mi lr ZO 
aan! : 
dye rope) 
vi 
ï il 3 
i : et 
rg P e 
s in vn 
= . ^ n + 
Disease surveys in agriculture rely on computer methods. This is a 
autopositive ready to be placed on a drum scanner. Totally black areas 
represent field acreages while blotches to the right of these images 
depict areas with diseases and other interpreted conditions. (Canada 
Department of Agriculture) 
Figure 6. 
  
Figure 5. 
The narrow beam of the foliage-penetrating 
radar altimeter penetrates to the ground 
surface. This contrasts with the conventional 
radar altimeter (right) with broad beam and 
signal reflected by the crown canopy. 
        
Figure 7. 
Thermal infrared mosaic of Western 
Lake Ontario. Prepared by the 
Canada Centre for Inland Waters. 
  
Figure 8. 
Unenhanced (left) and enchanced (right) small-scale aerial 
photograph. (Canadian Forestry Service) 
  
14