The CPA is traditionally calculated using vector geometry. Determine Relative Velocity ( Vrcap V sub r
The is the estimated position where the distance between two ships (the "own ship" and a "target vessel") reaches its absolute minimum. It is the primary metric used by Watchkeeping Officers to assess the Risk of Collision (ROC) . If the CPA is too small, a collision is possible, requiring immediate maneuvering according to COLREGs . 2. Core Parameters The method relies on two primary mathematical outputs: Ocean CPA method.pdf
The direction of the target's movement relative to the own ship. The CPA is traditionally calculated using vector geometry
Incorporating Rate of Turn (ROT) and Change of Speed (COS) into AIS-based predictions for more accurate results during maneuvers. If the CPA is too small, a collision
💡 While the basic CPA method provides a "point-in-time" safety check, modern ocean navigation requires combining CPA with Ship Domain models to ensure reliable collision avoidance in busy shipping lanes. If you'd like, I can provide: The specific mathematical formulas for DCPA and TCPA A summary of COLREG rules related to collision avoidance
Modern "Ocean CPA" calculations typically integrate data from two primary systems:
Recent research, such as that found on ScienceDirect and ResearchGate , suggests improving basic CPA by: