1971, and that effort will be exceeded in the 1972 and 1973 surveys of the 

 Caribbean, Northeast Atlantic, and North Pacific. 



The Navy's oceanographic survey capability has been increased in other 

 ways as well. The three survey ships are outfitted with the most modern 

 oceanographic and geophysical survey systems, including a computer-cen- 

 tered Oceanographic Data Acquisition System (ODAS). This new ODAS 

 unit was brought to operational status in 1971, and its employment to date 

 indicates this system will greatly improve data-handling capabilities. The 

 second improvement was the successful implementation of acoustic measure- 

 ments from oceanographic aircraft. Utilization of aircraft and sonobuoys 

 for ambient noise and reverberation measurements allows significant reduc- 

 tions in the time necessary to complete coverage of the extensive oceanic 

 areas with priority requirements. 



Oceanographic surveys in coastal and inshore areas to acquire environ- 

 mental data directly applicable to mine warfare, shallow water ASW, and 

 special warfare planning and operations will continue in cooperation with 

 two European and two Asian countries. These special surveys are carried out 

 under bilateral agreements and utilize host-nation naval ships and military 

 scientists working with Navy scientists. Among the characteristics examined 

 are acoustic propagation, current structure, and sea-floor and subbottom 

 sediments required for effective mining, mine-countermeasures, and other 

 naval operations in shallow water areas. Special surveys in strategic straits 

 are also carried out to provide data required to improve various ASW bar- 

 rier systems and concepts. These operations provide data concerning the 

 temporal and spatial fluctuation of the ocean currents, sound velocity struc- 

 ture, and the ambient noise field. Two extensive surveys were successfully 

 completed in the Denmark Strait; one in direct support of an ongoing fleet 

 exercise and the second as part of the continuing ASW support program. 

 In both cases, emphasis was on determination of current velocity and physical 

 properties of the Strait's complex structure. 



Utilization of Navy's capability to conduct high-resolution surveys of the 

 sea floor is increasing, with operations such as those noted in chapter II 

 and in special surveys of submarine trial areas. The capability of the deep- 

 tow systems is being improved steadily by a dedicated program of system 

 development. 



The capabilities for airborne surveys will be greatly increased by the re- 

 placement of existing planes by P-3 series aircraft in the near future. The 

 geophysical aircraft, currently a C-54, will be replaced when a new P3-D 

 configured for geomagnetic surveys becomes operational in 1972. The two 

 oceanographic NC-121 aircraft also are tentatively scheduled to be replaced 

 soon by P3-A aircraft as P3-C aircraft are phased into fleet ASW patrol 

 squadrons. 



Coastal and deep-ocean survey operations, plus source data obtained 

 through international cooperative agreements, resulted in the production 

 of 162 new or new-edition charts; over 600 corrected reprints of existing 

 charts; 36 new-edition oceanographic atlases, graphics, and publications 

 supporting ASW, mine warfare, and countemieasures ; over 12,000 messages 

 concerning maritime safety; 12 new editions of Fleet Guides and the first 

 three volumes (on the Mediterranean) of a new 43-volume sailing direction 



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