satellite constellation

A system of 24 satellites that is owned by the US Department of Defense (DOD) that can determine GPS location to within inches. There are usually at least 4 of these satellites that are in view 24 hours a day. The DOD can intentionally introduce error into the signal during national emergencies. This error called “Selective Availability” would allow an accuracy of approximately 50 yards without differential correction.

Authorization Path: 2.5.6.4.25.0