66 



TRANSMISSION EXPERIMENTS 



FREE SPACE 



08 BELOW 1 WATT 

 70" 



21 5 



SEPT 16 



10 



20 



"PINE"(57-FT STATION) 



SEPT 17 



II 16 21 



SEPT 18 



2 7 12 



TIME IN HOURS 



17 22 



FREE SPACE 



II I II I 



"BEACH" (16-FT station) 



SIGNAL LEVEL AS A FUNCTION OF TIME 

 SEPT 16 TO 18 



Figure 10. Variation of signal strength over 3 days. Two receivers on S band, Flathead Lake, Montana. 



path itself is entirely over water, the over-water There is, in this graph, a rather clearcut distinction 



trajectory of the air is limited by the dimensions between periods of standard propagation with a 



of the lake. Both receiving stations are below the comparatively limited margin of variability of the 



line of sight, the upper by 91 ft, the lower by 132 ft. signal, and periods of superrefraction accompanied 



