TRACKER GUIDE & MISSION EXPLAINER
GPS Satellite Tracker: Medium Earth Orbit and Navigation Explained
The Global Positioning System is a United States-owned positioning, navigation and timing utility. The directory above lists catalogued GPS spacecraft and allows an individual satellite to be followed on the map. Tracking orbit is different from calculating a receiver position, but the two ideas are closely connected.
GPS satellites operate in medium Earth orbit at approximately 20,200 kilometres altitude and circle Earth about twice per day. The constellation is arranged so receivers can observe signals from multiple satellites and solve for position and clock offset.
Space, control and user segments
The space segment broadcasts precise time and orbit information. A worldwide control segment monitors spacecraft, analyses their orbits and uploads navigation data. The user segment includes receivers that measure signal travel times from several satellites.
Your phone does not simply point to the nearest GPS satellite. It combines timed signals from multiple spacecraft. SpaceTracker.live shows an educational orbit view; it is not a GNSS receiver and does not decode navigation messages.
How to use the GPS tracker
- Choose one GPS spacecraft by name or NORAD ID.
- Observe the higher altitude and slower ground motion compared with ISS.
- Inspect the repeating medium-Earth-orbit track.
- Set a location to see when that satellite is geometrically above your horizon.
- Compare several spacecraft to understand why a constellation is needed.
How the calculated position is produced
The tracker propagates a public orbital element set with SGP4 and converts the result into map and observer coordinates. This is separate from the broadcast ephemeris used by an operational GPS receiver. The page should therefore not be used to test navigation accuracy or satellite health.
A satellite can be above your horizon without being usable by a specific receiver, and an orbit catalog can include spacecraft that are not currently set healthy in the navigation message.
Educational experiments
Compare GPS with low Earth orbit and geostationary satellites to see how altitude changes orbital period, ground speed and coverage footprint. Students can also explore why accurate timing is fundamental: distance is inferred from how long a radio signal takes to travel.
The tracker makes constellation geometry visible, but precise positioning requires signal corrections, receiver calculations and authoritative navigation data beyond this page.
Why geometry affects positioning quality
A receiver works best when visible satellites are spread across the sky rather than clustered in one direction. This spatial arrangement is described through dilution of precision: even perfectly timed signals can produce weaker geometry when the lines of sight are similar. Opening several GPS trackers and noting their azimuth and elevation provides a qualitative introduction to that idea. Accurate navigation still requires the receiver's broadcast data, corrections and measurement processing, which are outside this page.
Frequently asked questions
How high are GPS satellites?
GPS.gov gives an approximate altitude of 20,200 kilometres in medium Earth orbit.
Can one GPS satellite determine my location?
No. A receiver normally combines timed signals from multiple satellites to solve for position and clock error.
Does this page receive GPS navigation signals?
No. It calculates orbit from public elements and does not function as a GNSS receiver.
Does appearing in the directory mean a GPS satellite is healthy?
No. Catalog presence and orbital tracking do not establish navigation-message health or operational status.
Sources and further reading
Educational-use note: SpaceTracker.live is an independent educational website and is not an official mission-control service. Positions, paths, distances and pass predictions are computed from third-party orbital elements or ephemerides. They may be delayed or approximate and must not be used for navigation, collision avoidance or safety-critical decisions.
Last reviewed: August 21, 2026