230 



TRANSHORIZON PARAMETERS 



A S 6 6 H J F M A M J J A S S H 

 6 3 I 29 26 24 21 18 17 14 12 9 7 4 I 29 27 24 22 

 1947 1946 



0.0 



Figure 6.1. Weekly means of measured field intensities of W2WMN and W2XEA at 

 Needham, Mass., compared with corresponding atmospheric surface refraction at 

 Boston, Mass. 



(After Pickard and Stetson, 1950). 



oofnAMOLASO 



Figure 6.2. Correlation of the received monthly mean field strength at Campu Sa Spina 

 and the gradient AN {between and 1000 m.) of the monthly median index of refraction 

 at Elmas. 

 (The values of field strength are those obtained after omission of superrefraction) . (After Bonavoglia, 1958) . 



