ARPA stands for Automatic Radar Plotting Aids and is a crucial system onboard ships designed primarily to improve the standard of collision avoidance at sea.
Understanding ARPA
ARPA is an advanced radar-based system utilized by mariners to predict the future position of tracked objects (like other vessels) and determine the risk of collision. Its main purpose is to enhance maritime safety by providing officers with accurate, real-time information about surrounding targets.
According to the reference, Automatic radar plotting aids are essentially utilized to improve the standard of collision avoidance at sea.
Key Functionalities of ARPA
The core function of ARPA is to automatically track targets detected by the ship's radar. By analyzing a target's movement over time, ARPA calculates its:
- Course: The direction the target is moving.
- Speed: How fast the target is moving.
- Closest Point of Approach (CPA): The minimum distance the target will come to your ship.
- Time to Closest Point of Approach (TCPA): The time it will take for the target to reach its CPA.
These calculations provide vital data for watch officers to assess potential collision risks and make informed decisions to alter course or speed if necessary.
Improving Collision Avoidance
Before the advent of ARPA, watch officers had to manually plot the positions of radar targets on a plotting aid or reflection plotter. This was a time-consuming and labor-intensive process that required significant skill and concentration, especially in busy waters or adverse conditions.
The reference states, "Primarily designed as anti-collision radar, the ARPA technology removed the chore of plotting targets manually on a reflection plotter or separate plotting aid."
ARPA automates this process, continuously tracking multiple targets simultaneously and presenting the data visually on the radar display. This automation:
- Reduces workload on the bridge.
- Provides faster and more accurate collision risk assessment.
- Allows officers to focus more on lookout and overall situational awareness.
In essence, ARPA acts as an intelligent assistant to the radar, transforming raw target detections into actionable collision avoidance information. It is an indispensable tool for modern navigation and maritime safety.
