Radar Observer · ARPA — Acquisition
Compared with manual acquisition, automatic target acquisition on ARPA:
- AAcquires targets entering set guard zones/areas without operator action, but can be swamped in heavy clutter or dense traffic✓ Correct
- BIs always more reliable than manual in clutter
- CCannot track more than one target
- DRemoves the need to keep a lookout
Explanation
Auto-acquisition flags targets crossing guard zones automatically, reducing workload, but in clutter or very dense traffic it may acquire clutter, miss weak targets, or overload. Manual acquisition of the most important targets is often more dependable. ARPA never relieves the duty (Rule 5) to keep a proper lookout.
Authority: IMO Performance Standards for ARPA; Navigation Rules Rule 5
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