That's cool! Reminds me of the way the Iranian most likely got control over a US drone a couple of years back. They jammed communication signals and faked GPS data when automatic "go back to home base" landing procedure kicked in. http://www.informationweek.com/security/attacks/iran-hacked-...
How can they fake the gps signal, the military uses encrypted GPS?
I imagine if signal was jammed and only C/A codes were rebroadcast the drone would use those instead of nothing.
edit: Assuming that navigation was relying only on GPS