ftNTENNA 



NOISE 



FACTOR 



Tea 58 "a 58 I" 



DISTANCE FROM AREA CENTER (MILES) 



158 



Figure 8. Daytime 45 MHz man-made "^ no.se .ode f« 

 altitudes of 10 and 80 thousand fee above a buj« o£ 

 Radio noise power, F (dB/KTb) , is plotted as 

 distance in miles from the city center. 



4.3 CONTOURS 



., i ,-»n nroduce contours of constant 

 Th e airborne man-made radio noise model can prod ^ ^ 



noise on the operation of MBCS. ^ 



«. hundred of the nations ^J^ ^ ^L^O noise in the 

 and military installations are «*" "^'Lif for the continental Unrted 

 computer program. 9 Noise calculation, are contours are cal- 



sSes on a rectangular gr id wi fJf^^Z e £ twe en 30 and 70 MH* at alti- 

 Llated from this grid of ^ '« ^"JJ ^ d nlght time conditions. Figure 9 



containing noise l<*« ^ dBj k less^ »>£ ^ on , rop , f this scale, 

 the 30 dB contours are too small toner 



13 



