Space radars track the very very small.

[StingrayOZ]

New space radars track small but deadly space junk - space - 29 March 2012 - New Scientist

The same cannot be said for the estimated 200,000 pieces of space junk between 1 and 10 centimetres across that we cannot see. Existing radars simply can't track objects of that size in orbit. That's a problem since they can damage crewed spacecraft like the International Space Station and the 24 GPS satellites that we depend on back on Earth

This has come up in a few discussions. And is a public source of roughly how accurate radars are becomming.

The improvements are put down to ....

Enter gallium nitride, (GaN) a semiconductor that can amplify very precise wavelengths in the S-band, allowing a reflected signal to be more easily sifted from noise. Raytheon has described GaN as "an essential discriminator for new radar programs like Space Fence", and it's thought that Lockheed has harnessed this material for their system as we

I've thought they have been using Gallium for ages in military applications. Perhaps a new adaptation in its use?

 

[gf0012-aust]

I've thought they have been using Gallium for ages in military applications. Perhaps a new adaptation in its use?

it's been used in some types of Lasers for years.....