SURVEYING THE OCEANS (HYDROGRAPHIC) 31 



Office has the responsibility along with that of maintaining a 

 Bathymetric Data Library for the Department of Defense. This 

 probably makes it the world's largest repository of bathy- 

 metric data. 



The ability to conduct precise surveys in the oceans far from 

 shore has been a reality only in the past few years. Limiting 

 factors, such as unsuitable echo-sounders and the surveyor's 

 inability to position his survey vessel with sufficient accuracy, 

 precluded the performance of precise surveys. Increased 

 submarine activity and other vital defense measures forced the 

 solution of these problems; as a result, the United States now 

 has precise self-contained inertial navigation systems, many 

 world-wide nets of long-range electronic positioning systems, and 

 a capability for positioning relative to orbiting satellites. These, 

 along with advances in echo-sounding and precision depth 

 recorders, have permitted the Navy to extend its precise surveying 

 into all the world's oceans. With new multiple-beam sonars, 

 surface survey vessels can chart the sea floor much quicker and in 

 far greater detail. To obtain still greater detail in water of great 

 depth it is necessary to get closer to the bottom through the use 

 of towed underwater devices or underwater survey platforms. 

 Research and development effort in support of oceanographic 

 operations is now being emphasized. 



Development of an advanced hydrographic surveying and 

 charting system has been initiated. A design study is being con- 

 ducted by the Experimental Astronomy Laboratory of the 

 Massachusetts Institute of Technology. This study will indicate 

 the most effective means of increasing the rate of hydrographic 

 data acquisition and will result in a preliminary design for a 

 prototype system. This design will be based on a shipboard com- 

 mand/control concept for hydrographic and topographic (coastal) 

 data acquisition, correlation, compilation, reproduction and 

 dissemination. The system will be composed of an aerial survey 

 subsystem, a hydrographic survey subsystem, and a shipboard 

 cartographic compilation and reproduction subsystem. 



GEODETIC SURVEYING 



Little publicized and often misunderstood outside the scientifc 

 community is the amount of precise and detailed work necessary 



