Radar Observer · ARPA — Vector Time
Lengthening the ARPA vector time setting will:
- AShorten the detection range
- BIncrease the radar's transmitter power
- CExtend the vectors to project targets farther into the future, making developing CPAs easier to judge✓ Correct
- DSwitch the display to head-up
Explanation
Vector time scales the length of all vectors to show projected positions after that interval (e.g., 6, 12 minutes). A longer setting makes it easier to see whether tracks will cross or clear, while a shorter setting reduces clutter in dense traffic. It does not change the radar itself.
Authority: IMO Performance Standards for ARPA
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