OCEAN ELECTRONIC NAVIGATIONAL AIDS 73 



RANGE SELECTOR. — Control for selection of range scale. 



RESOLUTION. — 1. Range. — The minimum range difference between two tar- 

 gets on the same bearing that will allow the operator to obtain data on 

 either target. 



2. Bearing. — The minimum angular separation between two targets at 

 the same range that will allow the operator to obtain data on either target. 



3. Elevation. — The minimum angular separation between two targets at 

 the same range and bearing that will allow the operator to obtain data on 

 either target. 



SEA RETURN. — The Indication on a Radar indicator caused by radio waves 

 being reflected by the surface of the sea. 



SHIP HEADING MARKER iSHM). — An electronic radial sweep line on PPI indicating 

 heading of own ship. 



SWEEP CIRCUIT. — A Circuit which produces at regular intervals an approxi- 

 mately linear, circular, or other form of movement of the beam of the cathode- 

 ray tube. 



TARGET. — Any object which will reflect a sufficient amount of signal to be 

 evident at the search set. 



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