In ARPA, CPA and TCPA represent what?

Prepare for the ARPA and Radar Operation Test. Enhance your skills with multiple choice questions, detailed explanations, and real-time simulations. Ensure maritime safety with confidence!

Multiple Choice

In ARPA, CPA and TCPA represent what?

CPA and TCPA describe the future geometry between your vessel and a target. They tell you the predicted closest distance between the two vessels and the exact time at which that closest approach will occur, assuming both continue on their present courses and speeds. This is derived from the relative motion between the ships: by comparing your own ship’s speed and course with (and the target’s), you project where you’ll be and where the target will be, then find the moment when you come nearest to each other. The bearing to the target is a separate piece of information about where the target is now, not the distance or time of closest approach, and current range is simply how far away the target is at the moment, not how close you’ll get. So the key idea is that CPA is the predicted closest distance, and TCPA is the time to reach that point.

CPA and TCPA describe the future geometry between your vessel and a target. They tell you the predicted closest distance between the two vessels and the exact time at which that closest approach will occur, assuming both continue on their present courses and speeds. This is derived from the relative motion between the ships: by comparing your own ship’s speed and course with (and the target’s), you project where you’ll be and where the target will be, then find the moment when you come nearest to each other. The bearing to the target is a separate piece of information about where the target is now, not the distance or time of closest approach, and current range is simply how far away the target is at the moment, not how close you’ll get. So the key idea is that CPA is the predicted closest distance, and TCPA is the time to reach that point.

More practice questions