From: Washington D.C.
Sometimes I think in computer games and models there's a tendency to think about things like, "this is a radar for detecting boats, therefore it detects only boats," when really it just means that it is pointed at the water, has software to show some preference for boat-like things, and hardware optimized to try to make boat-like things more visible. That doesn't mean it only picks up boats, though. It picks up radar reflections, and depending on how the radar is set up, it might pick up things that are not boats but none the less generate a radar reflection (chaff and other decoys are great examples!). Some of those things are just as useful to know about as boats. Then there's the human factor, which is whether the operator would be able to determine that a given radar target is not a boat, and is in fact some other boat-like-in-some-way thing that the radar optimized for finding boats just happened to pick up?
Radar... so much to nerd out on...
That's actually a good point, most surface-search radars have some residual capability against low-altitude air targets.