TABLE II -1 (Continued) 



System 

 Inertia 1 



Acoustic 

 Doppler 



Estimated 

 Useful Range 



3-12 hours 



< 3 00 ft 

 water depth 



Estimated 

 Accuracy 



<2.0nm/hr 



Frequency 

 Range 



1% of velocity 0.2 -Imc 



^ 1% of distance 

 travelled 



Comments 



Must be checked with outside 

 reference, accuracy decreases 

 in a few hours at rapid rate, 

 very expensive, requires ex- 

 pert maintenance . 



Simple systems require a 

 manual plotting board and 

 complement standard dead 

 reckoning procedures; sophis- 

 ticated high -accuracy sys- 

 tems utilize gyro-compass, 

 velocity input, and automatic 

 track -plotting equipment. 



arthxir ai.llittlf.Ilnr. 



