Well, radar will get you a location, but lacks detail. Russia's Krona system[1] apparently uses radar to find the satellites, then illuminates them with a laser

Well, radar will get you a location, but lacks detail. Russia's Krona system[1] apparently uses radar to find the satellites, then illuminates them with a laser so that optical telescopes can get imagery and precise measurements. [1]http://geimint.blogspot.com.au/2008/06/soviet-russian-space-surveillance.html http://geimint.blogspot.com.au/2008/06/soviet-russian-space-...