HANNA: DESIGN OF TRANSMISSION LOSS EXPERIfffiNTS 



Mr. Swing: Why was the reflected path from that sub-bottom inter- 

 face terminated where it was? I don't understand that. 



Dr. Hanna: I'm sorry, which reflected path? You are talking 

 about the one which reflects at the interface itself? 



Mr. Ewing: No, that reflects at the deeper interface. 



Dr. Hanna: Oh, down here. 



Mr. Ewing: Yes. 



Dr. Hanna: In this particular case, they have simply come down 

 reflected and they do return into the problem, but way back in here. 



Mr. Ewing: And then what? 



Dr. Hanna: Well, for me, and then nothing, because I was inter- 

 ested in these ranges here and those correspond to the very short 

 ranges which I wasn't really discussing at this point. 



Let me try to remember another one of Will's slides. 



He showed measured transmission loss as a function of range for, 

 I guess it was — wasn't it — the Caribbean? 



Mr. W. H. Geddes (Naval Oceanographic Office) : That was the 

 Caribbean. 



Dr. Hanna: Yes. And if you remember, going from long range 

 into decreasing range there was a very abrupt transition in trans- 

 mission loss at around — I don't know, it was around this range 

 right here, if I remember correctly, 24, 28 kiloyards, something 

 like that, where the transmission loss abruptly dropped and went on 

 back to the ranges corresponding to this part of the problem here 



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