EXPONENTIAL MODEL 



69 



atmosphere for greater distances and heights. For a range of 600 mi, 

 where the ray reaches heights of about 200,000 ft, the 4/3 earth ray is 

 some 9000 ft lower than the N s = 400 reference atmosphere and 36,000 ft 

 lower than the N s = 250 reference atmosphere. This height discrepancy 

 is due to the 4/3 earth model's unrealistically large A'^ gradient at great 

 heights with resultant increased bending. 



,"^3e^.^ 



Figure 3.7. Comparison of rays in the CRPL reference refradivity atmospheres — 1968 

 and the 4/3 earth atmosphere. 



t^=S' 



3.8. Comparison of rays in the CRPL reference refradivity atmospheres — 1968 

 and the 4/3 earth atmosphere. 



