MR. J. M. SNODGRASS (SIO): I do not know of any but I can make 

 some estimates for some materials. In some plastics in which you 

 have different strength ratios depending on the axis, I would ex- 

 pect variations, but I do not know of any. 



MR. LEE HELiSER (Fairchild Camera and Instrument Corporation): 

 What are the bandwidth limitations for: Data transmission via 

 hard wire in instrumentation tow cables for cables that have been 

 proven suitable for \indersea oceainographic work? 



MR. J. M. SNODGRASS (SIO): I do not know precisely. This 

 question was a little confusing as stated. I will answer, assuming 

 he is thinking of either acoustical transmission of the signal along 

 the cable or electrical transmission. In this case, I am assuming 

 the cable has no electrical insulation on it. I know relatively 

 little about acoustical transmission. There are some background 

 noise problems that enter into this one because simply the nnotion 

 of cable through the water generates a wide noise spectrum. The 

 other, the matter of transmission of electrical energy along un- 

 insulated cable, can be done to a certain extent but is not very 

 economical of power. 



MR. LEE HELSER (Fairchild Camera and Instrument Corporation): 

 Is there a "Sonar Telemetry System" and if so, what are its 

 practical bandwidth limits? 



MR. J. M. SNODGRASS (SIO): There are some very good ones. 

 Some of you may have read the reports of the bathyscaphe, 

 Trieste, in the Mindinao Trench which had voice commvmications 

 with the surface at all times. This was an acoustical channel that 

 could well be used for telemetry, a single sideband- suppressed 

 carrier transmission. 



MAJOR GENERAL K. P. McNAUGHTON (Fairchild Camera and 

 Instrument Corporation): To what accuracy will shipboard gravity 

 meters measure the force of gravity? 



DR. A. E. MAXWELL (ONR): I am not quite sure of the accuracy 

 that can be measvired now. This depends, of course, a great deal 

 upon the ship, if the gravity meter is on a large ship, and a stable 

 platform, it could measvire as accurately as plus or minus one or 



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