Direct perception of collision danger information for safe marine navigation

Collision avoidance is a crucial operative task in marine navigation. The potential consequences of a ship-ship collision could be catastrophic with human losses and environmental pollution. Though the universal use of automatic radar plotting aid (ARPA) system on board ships has greatly reduced the risk of collisions, ARPA is insufficient to support operators´ direct perception of potential collision danger and knowledge-based problem-solving behaviors. Therefore it is imperative to visualize collision-related information graphically in an interface. The authors introduce the limitations of current ARPA display and point out that visualization of a collision danger line (CDL) and a collision danger sector (CDS) to an acquired target in true-motion interface is a practical approach for the navigator to detect potential collision danger directly and take suitable evasive actions well in advance of a developing situation. A CDL/CDS display has been developed and evaluated subjectively. It is argued that this display is promising and has the potential for real application. A simulator test program is currently being planned to further investigate the potential.