This data set contains the orbit characteristics of several well-known orbits engineered for specific applications:
Global Positioning Satellites (GPS) ==
The GPS constellation was originally designed to have 24 satellites, eight each in three approximately circular orbits. The original constellation architecture was changed to have six orbital planes with four satellites in each orbital plane.
The satellites are arranged to provide coverage by at least six satellites at all times for most locations on the Earth.
As of December 2012, there are 32 satellites in the GPS constellation. The additional satellites provide increased precision in GPS receivers. With the increased number of satellites and some more recent changes to the constellation, nine satellites are visible from any point on the Earth.