More details on reliability in CPA calculations
Provides GPS-based data including SOG (Speed Over Ground) and COG (Course Over Ground). 4. Calculation Methodology
The direction of the target's movement relative to the own ship. Ocean CPA method.pdf
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:
Defining a "safe zone" around a ship rather than a single point. More details on reliability in CPA calculations Provides
Uses radio waves to track the relative bearing and range of nearby targets.
Calculated by dividing the relative distance projection by the relative speed. The is the estimated position where the distance
The perpendicular distance from the own ship to the target's relative motion line. 5. Advanced Refinements