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

 FOR THE FREQUENCY RANGE FROM 1 HERTZ TO 5 KILOHERTZ 



physical situation as discussed with respect to Figure 14 indicates 

 that it is realistic. 



In suinmary, this paper describes and compares results of 

 statistical analyses of long time series of ambient noise obtained 

 in widely different geographic areas. These analyses include average 

 level versus frequency, average level versus depth for several fre- 

 quencies, cross correlation of level with wind speed versus frequency 

 and decorrelation time versus frequency. In addition, the determin- 

 istic effect of surface interference on directional noise received at 

 shallow hydrophones is discussed with respect to a measured data set. 

 The possibility is raised that noise in the deep ocean in the vicinity 

 of Bermuda displays significant wind effects in the frequency range 

 10 to 100 Hz with spectral shape different from that previously supposed. 



ACKNOWLEDGEMENTS 



This paper was prepared under Ocean Science Department overhead. 

 Analysis techniques described were previously developed under Project 

 A65005, Subproject SF52 552 702, Task 11286, "Ambient Noise Character- 

 istics Affecting Sonar and Physical Oceanography." The principal 

 investigator is R. L. Martin. The sponsoring activity is NAVSEA 05H1, 

 Mr. A. Franceschetti . Much of the data reported were acquired under 

 Project A65015, "Long Range Acoustic Transmission Experiments for 

 Surveillance Systems Development." The principal investigator is 

 R. W. Hasse. Subproject and Task No. R2408 sponsored by ONR102-OS, 

 Dr. R. D. Gaul. 



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