SUttMiLKT 



An airborne man-made radio noise rr.odol has been developed and programmed 

 on a graphics computer at the Naval Ocean Systems Center. This model provides 

 a useful approximation to the geographical dependence of airborne man-mode 

 radio noise in the continental Uni' e \ States. Radio noise maps produced from 

 thio model are used to evaluate the effect of man-made radio noise on the 

 operation of meteor burst communir >tion systems. 



Equations developed by Skoiaal (EN Skomal, Han-Made Radio Noise , Van 

 Noatrand Reinhold Co., New York, 1978) are used to construct the model. Two 

 parametric equations are used to model the height gain of man-made radio noise 

 ao a function of distance, to 150 mileB, from the source. Coefficients for 

 these equations are calculated from data measured over Seattle (WE Buehler and 

 CD Lunden, IEEE Trans. Electromagnetic Compatibility , EMC-8, 143-152, 1966). 



Two hundred of the nation's largest cities and 62 of the largest counties 

 and military installations are used as sources of radio noise in the computer 

 program. Day and nighttime contours can be produced in the 25 to 75 MHz range 

 for altitudes between 30 and 70 thousand feet. 



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