[comboy]

But it's still a mobile phone transmission power (1W?) and then r^2. Distinguishing that from noise seems mind-boggling.

[dzhiurgis]

Really just makes one think what sort of capability military has.

[JaimeThompson]

Check out the Orion series of Sigint birds[1]

" The satellites have estimated mass close to 5,200 kg and very large (estimated 100 m diameter) radio reflecting dishes."

[1] https://en.wikipedia.org/wiki/Orion_(satellite)