ADDENDUM TO "RADIO PROPAGATION OVER PLANE EARTH" 577 



The second paragraph of the footnote referring to equation (17) 

 should read : 



The differential equation given by Wise for ^IIo becomes 



~ ^A'dd^'^ dd~d) ^^^ ^ \ r+72 ^ r=^* L 2^ddj\ "•■ {2widl\y J j ^''' 



when the value of >> = (1 + t^)4IIo is substituted in his equation (7) and the result 

 divided by 1 + r^. The i of this paper is equal to — J in Wise's paper. By inter- 

 changing ^1 and k-i in Wise's equation (7) and proceeding along parallel lines the 

 corresponding equation of DYVo = y/{l + t-) is found to be 



4Ti^\dd^^ dddj ° V 1 + r2 1 - r* L 2wid/X "^ {2irid/Xy J / °" 



Adding these two relations gives an expression for I —-7^ ")" j^ ) H, where 



n = 2{A + D)no, 



which when substituted in the above equation for E and the result divided by 2Eo, 

 where Eo = — 240iw'^Tlo/'X, gives equation (17). Since Eq is the inverse distance 

 component of the free space field, this relation for Eq follows from equation (11). 



In the last line of the footnotes on page 51 read 2/(1 + t^) for 

 2/(1 - r"). 



