0g* ■'£F*maiw*tMiW3&ii. 



h&t-r 



a 





CONTOURS: Ft (dB'kTb) 



Figure 14. Nighttime 45 MHz airborne man-made radio noise 

 map of the continental United States for an altitude of 

 70 thousand feet. 



Figure 15. Daytime 30 MHz airborne man-made radio noise 

 map of the continental United States for an altitude of 

 30 thousand feet. 



17 



