They have a pretty interesting description of their radar images: "...because of how strange the world looks in radar. Photons of that wavelength travel easily through fog, dust, rain and snow, but anything metallic looks like a mirror. The radar can see people, but they appear partially translucent. Something made of wood or painted plastic, though opaque to a person, is almost as transparent as glass to radar".

So my question is, where can I find such images? Or can I buy such a radar and tinker with it myself? What wavelength are they speaking about?