eXcess 
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ted to 
obtained 
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r national 
rview is 
us, near 
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rs which 
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h widths 
Force, 
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n 16 
ence and 
f major 
n energy 
f the 
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| in the 
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Fig. 5 DMSP nighttime image of eastern United States. 
Illuminated urban areas (IUA's) may be easily dis- 
tinguished in areas not masked by clouds. 
  
  
Fig. 6 The IUA as a three-dimensional domed figure in 
which the z-coordinates are proportional to energy 
consumption.