THEORY AND RESULTS 



153 



20 



40 



60 80 100 120 140 



DUCT HEIGHT ,h, IN m 



160 



180 200 



Figure 4.44. Shadow zone half-lengths for maximum ducting conditions at 



Washington, D.C. 



o 



1,000 

 700 

 500 



300 

 200 



100 

 70 

 50 



30 

 20 



10 

 7 



20 40 60 80 100 120 140 



DUCT HEIGHT . h , IN m 



160 



180 200 



Figure 4.45. Shadow zone half-lengths for mean ducting conditions at 

 Washington, D.C. 



