GPS (Global Positioning System)
US satellite navigation constellation. ~31 active sats in MEO at ~20,200 km.
Counts objects currently in our catalog by their launch year, so earlier years read lower than the number originally launched — deorbited members are no longer tracked.
Grouped by COSPAR launch designator — every object from one rocket shares it, so these are exact groupings. Counts are members still in the catalog, not the number deployed.
Mean altitude ((apogee + perigee) / 2) in 10 km bands, from current orbital elements. Distinct spikes are maintained operational shells; a smear is an uncontrolled or drifting population.
Orbital planes in 1° bands. Several sharp peaks mean the constellation is built from discrete inclination groups, each covering a different band of latitudes.