758 THE BELL SYSTEM TECHNICAL JOURNAL, MAY 1954 



1.0 

 0.9 



5 0.4 

 < 



CO 



3 0.3 



O 



-5 -4 -3-2-1 1 2 



Fig. 23 — Impulse transmission chamcteristics with cosine variation in delay. 



corresponding point obtained by the method illustrated in d of Fig. 20 

 is 



P = 1-0.365 4- 0.85 (0.39 + 0.05) 



-H 0.5 (0.26 - 0.328) + 0.15 (0.131 

 = 0.70. 



0.178) 



In Fig. 23 are shown the resultant pulses obtained by the above method 

 for various values of h and the corresponding values of c?ma,x/mas • Since 

 the interval between pulse echoes is small in relation to the duration of 

 the pulse Po(t), as seen from Fig. 22, the individual pulse echoes cannot 

 be discerned in the resultant pulses shown in Fig. 23. It will be noticed 

 that as h increases, the pulses are received with decreasing transmission 

 delay, which is due to the choice of reference delay in the delay distor- 

 tion curve. That is, as dmax or h is increased, the delay becomes increas- 



