also is recorded, as is suggested. This system is treated briefly in 

 Section II. 



FM transducers already exist; however, they are rather complex and 

 somewhat unstable. Although they appear to be superior in many res- 

 pects, extensive engineering and testing will be needed to provide the 

 reliability required. In the meantime, less sophisticated transducers 

 can be employed in such a system by converting voltage output to 

 frequency prior to recording. Standard, moderately priced components 

 are available commercially for this use. Some of these components 

 have been used successfully by the Office for recording on magnetic 

 tape. 



It is the recommendation of the Committee that continued develop- 

 ment and testing of this system be supported with the necessary funds 

 and be given a high priority. 



This system will require some modest development or modification 

 of transducers. It is believed that the following measurements can 

 most readily be incorporated into such a system: (1) temperature, 

 (2) depth (pressure), (3) salinity, with sufficient accuracy for use in 

 coastal waters only, (4) light attenuation, (5) currents, with some fur- 

 ther development, and (6) sound velocity. 



After extensive field testing of such a limited system, which should 

 require about six months, the Hydrographic Office should begin to 

 instrument one of its survey vessels for more extensive collection of 

 geophysical (oceanographic, bathymetric, etc.) data. Recording should 

 be centralized and as automatic as the state of the art permits. The 

 objective would be to further develop and field test a prototype of a 

 comprehensive data collection system and to gain experience for 

 directing its continued improvement. The Hydrographic Office is 

 already gaining valuable practical experience along this line in its 

 instrumentation of a submarine for oceanographic measurements. (See 

 Appendix C.) This experience should next be applied to the broader 

 problem of equipping a surface survey vessel for more extensive 

 geophysical measurements meeting survey specifications. 



Improvement and extension of this system for other measurements, 

 and incorporation of more sophisticated techniques of measurement, 

 relay, and recording of data, should be continuing objectives of the Of- 

 fice. It is in furtherance of this long-range objective that consultation 

 and continued liaison with key individuals in the field of oceanographic 

 instrumentation and related fields is proposed. 



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