64 OCEAN ELECTRONIC NAVIGATIONAL AIDS 



Minimum — 500 yards. 



Accuracy — ±5 percent or ±500 yards whichever is greater. 

 Bearing: 



Equipment must be capable of giving an over-all bearing accuracy of 



±5° using as a target a C2 cargo vessel or equivalent at a distance of 7 



miles. 



V. Indication and Output 3ata — 

 Indicator: 



5 inch scope or larger; PPI (plan position indicator) preferred. 

 Range: 



Electrical or mechanical to meet requirements of paragraph IV. 

 Bearing : 

 Mechanical dial or equivalent. 

 Positive means should be provided to indicate whether or not the over-all 

 operation of the Radar is such that it may be relied on to provide effective 

 anticollision and navigational information. 



VI. Frequency — 



Any channel authorized for use of commercial Radar. 



VII. Antenna — 



A motor-driven train is to be provided, with arrangements for shifting to 

 manual train for bearing determination. Minimum speed of rotation, 5 revo- 

 lutions per minute. In case an A scope is used, it is to be understood that it 

 must be continuously manned by trained personnel if the anticollision features 

 are to be realized. Should a PPI scope be used, the provision for hand train 

 may be eliminated and the speed of the rotation may be increased to 15 

 revolutions per minute. The beam width in the vertical plane must be at 

 least 20°. 



