NAVIGATION 



(A) Instruments for measuring angles and distances. 



I. Angle measuring 



Angle read to 1"; estimated 

 to 0. 5". 



a. T-2 Theodolite 



(H. Wild Co. , Switzer- 

 land) 



Azimuths determined to 



within 1 " of arc. 

 Distance of measuring line: 



10 to IZ nautical miles. 



b. T-3 Theodolite 



Angle read to 0.2". 

 Distance of measuring line: 

 25 to 30 nautical miles. 



c. T-4 Theodolite 



Angle read on horizontal 



circle to 0. 1 " 

 Angle read on vertical 



circle to 0. 2". 



2. Levels (Wild Models N-II and 



N-III) 



3. Distance nneasuring 



a. Geodimeter -- NASM-2 

 (AGA, Sweden) 



b. Telluromieter 



(Teliurometer , Ltd., 

 South Africa) 



Maximum) range: 38 to 40 



nautical miles. 

 Accuracy: 6 ft. 



Maximum range: 38 to 40 



nautical miles. 

 Accuracy: 20 ft. 



(B) Electronic positioning systems (Navigational Aids). 

 1. Hyperbolic Systemis 



a . Loran-A (Ljng-range 

 accuracy) 



Range (useful): approxi- 

 mately 200 nautical 

 miles . 



Accuracy: 15 ft. on base- 

 line; 400 ft. at outer 

 limits of usable area. 



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