RADIO PROPAGATION FUNDAMENTALS 



617 



elude the effect of diffraction and average refraction around a smooth 

 spherical earth as discussed in Section III, but do not include the iono- 

 spheric effects described in the next Section. The increase in signal ob- 

 tained by raising either antenna height is shown in Fig. 14 for poor soil 

 and Fig. 15 for sea water. 



50 

 45 

 40 



ui 35 



m 

 m 

 O 30 



LU 



a 



-r 25 



? 20 



< 



O 



H 15 



I 



O 



^ 10 



-5 



6 7 8 9 10 



20 30 40 50 60 70 80 100 



ANTENNA HEIGHT IN FEET 



200 



Fig. 14 — Antenna height gain factor for vertical polarization over poor soil. 



40r 

 35 

 ^ 30 



LU 

 ffl 



O 25 



LU 

 Q 



Z 20 



15 



^,0 



6 7 8 9 10 



20 30 40 50 60 70 80 100 



ANTENNA HEIGHT IN FEET 



200 



Fig. 15 — Antenna height gain factor for vertical polarization over sea water. 



