20 
For Ocean Surveys, the following navigational criteria 
have been developed: 
(1) The system must cover the world ocean in its entirety; 
however, all areas need not be covered at the outset of the 
program. 
(2) Two basic systems are needed to cover all types of oceano- 
graphic operations: a short-range system with accuracies of 
+ 100 feet at a maximum range of 200 miles from shore, and 
a long-range system covering the rest of the ocean with an 
accuracy of + 3 mile. 
(3) The shipboard equipment must be suitable to installation 
on a variety of ships, must have a high reliability, be 
easily operated and maintained, be relatively light-weight 
and compact for installation on all ships engaged in Ocean 
Surveys, and must be suited to easy dismantling, removal, 
and relocation on another vessel. 
(4) The shore installation must have an on-the-air time in 
excess of 95 per cent, the signals must be free of ambiguity, 
and the system must be capable of simultaneous use by many 
ships. 
(5) Neither the operation of the system (from land stations 
or from satellites) nor the shipboard equipment should be so 
expensive that sheer cost alone precludes its use by all 
ships operating on Ocean Surveys. 
