Study on function improvement of automatic radar plotting aids and evaluating of the support effect

This paper discusses functional improvement of ARPA (Automatic Radar Plotting Aids) and its effectiveness for the prevention of collision. In sea traffic, since ships are operated by the limited number of watch officer, there are some problems of preventing possible human errors when avoiding collision situation. To prevent possible collision accident, it is vitally important that the support function of assessing collision risk by ARPA should be improved and its effectiveness of support should also be assessed. To solve this problem, we recommended in this study and advanced ARPA in which navigational and environmental assessment function and avoiding and maneuverable assessment support function are added to and incorporated into the function of the conventional ARPA. We also discussed and studied on the effectiveness of avoidance with display from the aspects of information reading and recognizing error, reliability of information indicated on the affordability of avoiding possible collision and effectiveness to reduce the danger in avoiding collision when ships sail and maneuver. After discussion and study, it was found that the support effectiveness by the advanced ARPA was far improved and recognized compared to the conventional ARPA indicating system. Improvements thus made cover the following; (1) It was found that information reading and recognizing error by the advanced ARPA has been considerably reduced compared to the conventional one. (2) With the advanced type ARPA in use, a ship is able to avoid the risk of entering dangerous area feared to collide with other ship simply by a judgment once made in maneuvering and avoiding collision of ship. (3) The danger of collision when ships sail and maneuver can be reduced to approx. 32% of the level when using the conventional ARPA indicating system.