practical at present and is being explored by this Office. 



It is recommended that proposals for such a development be invited 

 and, if bids are within the funding capability of the Hydrographic Office, 

 that contracts be let; otherwise, the Office of Naval Research should 

 be requested to sponsor the development of this instrument. 



Although the Wiancko pressure measuring system has been satis- 

 factory for the limited application to which it has been put by the 

 Hydrographic Office, it does not appear at present to be sufficiently 

 dependable for obtaining wave records over a period of several 

 months, which is the most pressing requirement of this Office in 

 inshore areas. The NOL, acoustic system which appears to be better 

 suited for this purpose is being tested by the Hydrographic Office. 



It is recommended that the possible application of a vibrating wire 

 transducer for wave measurements be explored. 



Better equipment for analysis of wave records for power spectra, 

 wave form, etc. must be obtained. Present equipment is slow and 

 limited in application. One wave analyzer similar to that used in the 

 David Taylor Model Basin seakeeping data analysis center (SEADAC) 

 has been purchased to facilitate the analysis of wave and ship motion 

 data at the Hydrographic Office. Although this analyzer is not yet 

 operational, it is expected that the system will allow more rapid 

 processing of this type of data. 



An airborne wave recorder is highly desirable. However, extensive 

 testing of existing instruments and exploration of suggested techniques 

 have not been promising and indicate that development of such an 

 instrument is probably beyond the present financial capabilities of 

 this Office. As has been previously suggested, the Hydrographic 

 Office probably should look to development of such an instrument by 

 the Bureau of Naval Weapons for operational use on seaplanes. 



It is recommended that all wave records be made on magnetic 

 tape for ease in processing and be supplemented by a visual record 

 for monitoring and other special purposes. 



J. RADIATION MEASUREMENTS 



Before confident recommendations can be made concerning radiation 

 instruments pertinent to the work of the Hydrographic Office, consider- 

 ably more experience must be gained in the use of equipment already 



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