Accuracy of satellite constellations concerns US military

A satellite constellation is a group of human-made satellites coordinated from the ground and synchronised to provide global coverage. The most well known of these is the American Global Positioning System (GPS) which, when it was commissioned in 1995, comprised 24 satellites orbiting at an altitude of 20,200 kilometres. The system was originally intended for military use but after Korean Airlines flight 007 was shot down over Soviet airspace in 1983, President Ronald Reagan announced that GPS would be made freely available for civilian use. Two hundred and sixty-nine passengers and crew were killed in the crash and the decision to allow open access to GPS was made to avert any similar navigational errors in the future. More

(Source: Stuff.co.nz - Jul 18)