fNCLASSIFIED 



SECUKITV CLARIFICATION Or THIS "AG£ (*?>««> c«« r-"< 



20. (Cont.) 



Coefficients for these equations ere calculated from data measured over Seattle (W. E. Buchler and 

 C. D. Lundcn, IEEE Trans. Electromagnetic Compatibility , EMC-3, 143-152. 1966). 



Two hundred of the nation's largest ctUes and 62 of the largest counties and military installa- 

 tions 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. 



S,N 0102- LF. 014-6601 



UNCLASSIFIED 



SBCUHITY CLASSIFICATION OF THIS PAGV"**" Dal* Bnltnd) 



fc. .i ... 



i »■ i'lrniiii'rT n n 



—J 



