2. Recommendations for development of new instruments and methods 



a. A small, portable instrument should be developed for measur- 

 ing absolute gravity with a probable error not to exceed 0.1 milligal. 



b. Development of a miniaturized, automatic gravimeter for 

 operational use by submarines should be initiated. This meter should 

 be as nearly automatic as possible with provisions for feeding the 

 raw data directly to a computer. The meter should be sufficiently 

 simple to be operable by one semiskilled person and should require 

 a minimum of maintenance. 



c. In view of the aircraft, presently in use by the Hydrographic 

 Office for Project MAGNET, development of an airborne gravity meter, 

 which could be utilized in conjunction with magnetic surveys, should 

 be encouraged and monitored by this Office. 



d. Each new gravity instrument developed for geodetic operations 

 should have world-wide range to avoid resetting problems and have a 

 calibration correction over its full range as nearly linear as practicable 

 (and, if possible, a constant). 



e. New methods of recording and processing gravity data from 

 ocean surveys should be investigated, and a system compatible with 

 data processing methods adopted for general use by the Hydrographic 

 Office should be developed. 



f. It is recommended that a continuing liaison be maintained by 

 this Office with commercial laboratories and other government activ- 

 ities engaged in development of new gravity instruments. In view of 

 the responsibility of this Office for ocean gravity surveys, final Navy- 

 acceptance of all instruments for this use should be subject to approval 

 after evaluation by the Hydrographic Office. Comparative tests of all 

 new instruments should be accomplished as rapidly as practicable and 

 witnessed by representatives of the manufacturers concerned, the 

 Hydrographic Office, and an impartial activity such as the Coast and 

 Geodetic Survey. 



XIII- 7 



