Big flat conductive panels make good reflectors.

That makes sense but my first thoughts were that panels wouldn't be oriented so that the majority of that flat surface was perpendicular to the radar but instead much closer to parallel, and that aviation radar would be higher up than a house roof to avoid ground clutter.

Wonder if it can be leveraged as for passive radar. Synthetic aperture also comes to mind.

I’m clueless in this field tho.