214 RADIO WAVE PROPAGATION EXPERIMENTS 
rather slow. The following method circumvents this For altitudes of less than 500 m it is safe to sup- 
difficulty for heights less than 500 m. From equations pose that = 
(4), (8), and (15) alae ( » +), 
T 273 273 
(n — 1) 108 = Fe -eh/7 (16) where ¢ is the average centigrade temperature, and 
TaBLe 8A. F(t, w) for t from —30 C (—22 F) to 40 C (104 F): w from 0 to 12. 
2 3 4 5 6 7 8 9 10 iF 
seipararaeae tl ff fo 0 
VOMA Kw ON PANO 
NPHOWDSONRPRPNOODP 
+ 
= 
