BACKGROUND 



177 



definite field strength changes may occur during frontal and squall line 

 passage. Caution should again follow in the interpretation of these 

 results since they represent but a single example of frontal and squall line 

 passage. 



Gray [18] made measurements of correlation of A^^ and the gradient on 

 N with path losses at UHF frequencies for observing points representative 

 of various climatic areas around the world and concluded that changes in 

 transhorizon telecommunications are strongly dependent on atmospheric 

 changes. 



400 



300 



2''-46'S., I7r-43'W 



FEBRUARY 1953-1957 



274 PROFILES, Ns=37l.3 



N 200 



100 







'UPPE^ AND LOWER 

 STANDARD DEVIATION 

 LIMITS 



EXPONENTIAL REEERENCE- 

 ATMOSPHERE, Ns=37l3 



2 4 6 8 10 12 14 



h (km) 



Figure 5.2. Mean N distribution for Canton Island, Pacific Ocean. 



