RECOMMENDATIONS 



I. THE UNDERWATER SPARK SOUND SOURCE 



1. Conduct tests with the underwater spark to determine its 

 suitability for converting existing passive coastal defense 

 systems into active systems. 



2. Conduct tests with the underwater spark to determine its 

 suitability for converting existing submarine passive equip- 

 ment into active echo- ranging equipment. 



3. Conduct tests with the underwater spark to determine the 

 feasibility of obtaining desired directivity by use of suitable 

 reflectors. 



4. Continue effort to determine the utility of the underwater 

 spark in fields of oceanography, hydrography, and seismology. 



5. Continue effort to obtain improved materials for electrodes 

 and gaps, as well as to determine possible upper power limits, 

 utility of resonators, etc. 



II. THE PNEUMATIC SOUND SOURCE 



1. Conduct tests to determine the usefulness of the pneumatic 

 source in converting passive coastal arrays into active ones. 



2. Conduct tests to determine the usefulness of the pneumatic 

 source in low- frequency echo- ranging operations from sub- 

 marines, helicopters, etc. 



3. Conduct tests to determine the usefulness of the pneumatic 

 source in other military applications, such as: 



a. Pre- cursor acoustic sweep in mine countermeasures 



b. Location of missile nose- cone water entry position 



c. Anti-limpeteer operations 



d. Submarine signalling 



e. Oceanography, seismology, etc. ' , 



4. Continue effort to obtain improved materials and to deter- 

 mine upper power and frequency limits. 



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