34 THE NAVY OCEANOGRAPHIC OPERATIONS PROGRAM 



ations have contributed greatly to a continuing search for more 

 exact knowledge concerning the size and shape of the earth and 

 the location of points on its surface. 



The future in this field appears exceptionally bright. 

 Navigational and geodetic satellites developed under Navy contract 

 are now operational. Their use has revolutionized the science of 

 geodesy, allowing fulfillment of a longtime dream of geodesists 

 to relate all points on the earth's surface to one reference 

 point— in this case, the center of the earth. Several such satellites 

 are now circling the earth in orbits approximately 600 miles in 

 space. By knowing the orbital parameters of the satellites and 

 by receiving radio signals from them, the geodesist utilizes the 

 Doppler principle in determining their closest points of approach. 

 From this information, a precise position is defined. 



Satellites have also proved quite successful for their original 

 purpose of "positioning at sea". Although here the situation is 

 more complex and underway measurements have presented some 

 problems, by programming information in addition to the orbital 

 parameters into the satellites and by retransmitting this to ships 

 equipped with Doppler receivers, an accurate position can be 

 obtained from only one pass of the satellite. This technique has 

 been operational for some time and has provided suitable posi- 

 tioning control for surveys conducted beyond the limits of existing 

 LORAN-C net. A recent Navy decision to make this technique 

 available for general navigation purposes will unquestionably 

 improve the navigational control of merchant ships and in turn 

 make them more valuable for collecting oceanographic data. 



MAGNETIC SURVEYING 



In 1953, the Naval Oceanographic Office inaugurated Project 

 MAGNET, an airborne geomagnetic survey of the accessible ocean 

 areas. Replacing specially constructed wooden ships that formerly 

 collected magnetic data in the oceans, the project has dramatically 

 increased the amount of data collected. It has allowed collection 

 of data in polar regions where little concerning the field had been 

 previously known. Currently, the project has two aircraft, an 

 NC-121 Constellation and an NC-54 Skymaster, conducting sys- 

 tematic and continuous world-wide surveys, generally flying along 



