Chapter 2  OPERATIONS 
2.13  SETTING TT/AIS 
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INSTRUCTION MANUAL 
2.13 SETTING TT/AIS 
This section describes the operations of TT and AIS. 
 
2.13.1  COLLISION AVOIDANCE 
 Problems of Collision Avoidance in Navigation 
Marine collision avoidance is one of the problems that have been recognized from of old. 
Now, it will be described briefly who the collision avoidance is positioned among the 
navigational aid problems. 
The navigation pattern of all mobile craft constitutes a system with some closed loops 
regardless of the media through which the mobile craft travels, whether air, water, the 
boundary between air and water, or space. This pattern consists of two closed loops in 
principle, one of which is a collision with another mobile craft and the other is a loop of 
finding a right and safe way to reach a predeterminate destination. 
Fig. 2.13-1 shows the conceptual diagram of navigation pattern by MR. E.W. Anderson. 
The closed loop of collision avoidance is shown on the left side and the closed loop of 
finding a right course on the right side. 
Fig. 2.13-1  Navigation Pattern