Realistically, isn't it a known presence on radar? It's static - you can't just ignore signals from that area in space?

Yes, and more...

You can use different antenna designs for a more directional radar beam. Or tilt the beam upwards to steer it around obstacles.

You can also build a moving-target detector by looking at doppler shift to filter out objects that are moving too slowly: https://en.wikipedia.org/wiki/Moving_target_indication

	▲	egberts1 a day ago \| parent [-]
		Curly blades makes it harder to lower its radar surface areas.

the_gipsy 2 days ago | parent | prev [-]

The enemy could be hiding precisely at the windmills /s

	▲	robocat 2 days ago \| parent [-]
		Perhaps if tip speed is X and radar installation is perpendicular to wind turbine, then an enemy can approach at speed X in the turbine's radar shadow. There would still be multiple pulses with timing differences but if there's a field of turbines then I'd guess there's enough interference/scatter to be a problem. Like using approaching from the sun causes problems for pilots. The reflections from the turbines would pulse due to the blades so in theory their scatter could be cancelled out in processing?