MARTIN/PERRONE : GEOGRAPHICAL VARIATION OF AMBIENT NOISE IN THE OCEAN 

 FOR THE FREQUENCY RANGE FROM 1 HERTZ TO 5 KILOHERTZ 



Mr. Martin: I'm glad to hear that, because during this particular 

 set of measurements I think we were heading back to port and only doing 

 about 4 knots and just trying to hang onto the bunk. There was quite 

 a gale. 



That may be the reason. I don't know. One of the problems is, 

 though, it is a short data set and you have to be careful what kind 

 of limits you put on the result. 



Dr. R. W. Bannister (Defence Scientific Establishment) : Is there 

 any set-down procedure for selecting data that is generally accepted 

 within the community? 



The concern I have is that I see some New Zealand data super- 

 imposed here. In that particular case, I know we excluded ships which 

 we were aware of. And I guess it depends what means you use to be 

 aware of ships. 



In other words, this is a very bad way of selecting things be- 

 cause it depends upon the eyes you have or the ears you have. 



Is there a criterion for selecting data so that we can superimpose 

 them in some rational way? 



Mr. Martin: We did exactly the same thing with the Bermuda data. 

 We just extrapolated through any nearby shipping. We eliminated 

 that portion that was easily identified as nearby shipping. So we 

 are only dealing with the longer range noise. 



Dr. Bannister: So this is an eyeball look at the record, is it? 



Mr. Martin: Eyeball and earball. We processed the data in real 

 time, so people were listening to it. 



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