Genuinely curious why would any one need a radar.

People studying weather, the atmosphere, birds and of course people expecting aircraft. :)

This particular radar is bloody expensive, though - its price tag is about 15 000 euros.

Other fun radar projects, most of them well above my head, so I won’t dare to wade in:

Henrik Forsten: home made polarimetric synthetic aperture radar drone (takes photographic quality radio images of ground, budget several kiloeuros + ability to fly or a high vantage point)

Radar Tutorial - old military guy explains all the concepts, provides many schematics and various formulas

WetterSat - Mobile amateur rain radar - helps you locate rain at 10.5 GHz within a 100 km circle, cost about 1500 euros

Daniel Kamiński’s blog - explains the principles of a GPU-accelerated passive coherent location finder (radar that uses non-cooperative external illumination sources like TV signals), cost a few hundred + a high end GPU, but completeness is low (hard to recreate)

It’s a key component to any well-integrated home air defense system.

At 95% less than $250,000, why wouldn’t you have one?

It gives you time to pull on your brown pants for the incoming drone invasion.

Not sure about personal usage but poor governments could save a lot on and have backups for fraction of the price.

Very handy for boats, planes, checking if Godzilla is on path for your house.

Uh, to see stuff?