Quote:
Originally Posted by vheissu  Lots of information here: http://en.wikipedia.org/wiki/Gps
Since it was developed by the US Department of Defense, do other countries have use of it, or have their own satellites? Can companies in other countries develop devices to use it? |
The system is owned and operated by the US, any country on earth may use the system if they have a GPS receiver. The US has a signal denial system that prevents anyone within a specific region, any region in the world dictated by the US govt, to use the GPS signal. The military PPS signal still works in those regions where active denial is taking place and only USA/allies with specific PPS GPS coded receivers can access the system.
Whenever we go to war we deny the enemy the use of GPS while our forces take full advantage of it. The only option an enemy would have would be an attempt to jam the PPS signal that is received on the ground for an area. Hence my post above, the USAF has some affective countermeasures to GPS jammers. This is one reason why the Air Force still maintains very well other targeting systems.
The only other satellite navigation/targeting system in use today is the Russian made constellation. The system is so dilapidated that only a handful of satellites even work still and the coverage area is a relatively small spot around the former USSR.
-Ryan