Quote Originally Posted by Armchairguy View Post
The reliance on satellites, especially GPS without alternatives is dangerous. I've thought that where possible towers and buoys could be used as a backup to GPS. It could be further extended by using positions of ships, aircraft and some ground units with continually updated positions acting as positioning points on their own. It probably wouldn't hurt to have access to the European and Russian GPS systems as well.
I recall reading somewhere about an idea to equip all aircraft (civilian and military) with some sort of responder that would act similar to a satellite. The idea is that with the amount of air traffic (especially commercial), we'd have near total global coverage. I've tried to locate the article again, but no luck.

Another aspect to this is China's anti-satellite shot back in January. If memory serves, the shot was from a mobile platform. The stuff I read didn't go much into specifics about the platform, but I wonder if this is something that can be built or bought by terrorists? Is it possible that a terrorist group could shoot down a key satellite that could cause immense damage for a lengthy period of time? Or what about a rogue nation doing the same thing? Or let me go way out on a limb here: is it possible that a critical satellite that controls movement in Iraq be taken out to coincide with a Tet-like offensive? I don't know the tech side here, so maybe I've ventured into the realm of the impossible.