What does GPS stand for? GPS stands for the Global Positioning System, a network of satellites owned by the United States government that broadcasts timing signals. A receiver on the ground, in a car, a plane, a boat or a phone, listens to several of those signals and works out where it is.
People also use GPS as a name for the device or the map app itself, as in "put the address in the GPS." Strictly, that device is a GPS receiver, and the system is the satellites plus the ground stations that keep them accurate.
Quick facts
Stands for
Global Positioning SystemType
Initialism, said G P SRun by
The U.S. military, for free worldwide civilian useHow it works
A receiver times signals from at least four satellitesGives
Position (latitude, longitude, height) and very precise timeRelated terms
GNSS, GIS, Wi-Fi location
GPS stands for Global Positioning System, piece by piece
| Letter | Word | Meaning |
|---|---|---|
| G | Global | Works anywhere on Earth with a view of the sky |
| P | Positioning | Finds a location, not just a direction |
| S | System | Satellites, ground control and receivers working together |
The system has three parts. The space segment is the group of satellites, usually around thirty in active use, circling roughly 12,550 miles up. The control segment is a set of ground stations that track the satellites and correct their clocks and orbits. The user segment is every receiver that listens.
What does GPS stand for in practice? How a receiver finds you
Each satellite carries very accurate atomic clocks and keeps sending out its position and the exact time. Radio signals travel at a known speed, so when a signal arrives, the receiver can tell how long it took and therefore how far away that satellite is.
With the distance to one satellite, you could be anywhere on a huge sphere. Add a second and a third, and the spheres cross at a small area. A fourth satellite fixes the receiver's own clock error, which is why receivers need at least four in view for a reliable fix. This math is called trilateration.
On a hiking watch: "Acquiring satellites... GPS ready." The watch has locked onto enough signals to calculate your position, so your track will now record accurately.
Where GPS shows up in daily life
- Driving directions and ride and delivery apps that show a moving dot on a map.
- Aviation and shipping, where pilots and captains use it alongside other instruments.
- Farming, where tractors can steer straight rows within inches.
- Surveying and mapping, which feed data into GIS software.
- Timekeeping: cell networks, power grids and banks use GPS time signals to keep their systems in step.
- Emergency calls, where a phone's location helps responders find the caller.
Why your phone location is sometimes off
GPS signals are weak by the time they reach the ground, and they do not pass well through roofs, tunnels or dense city blocks. Tall buildings can bounce signals and add error. To fill the gaps, phones also estimate location from nearby Wi-Fi networks and cell towers, and they use data from the motion sensors inside. Outdoors with a clear sky, a typical phone is often accurate to within a few yards.
Other countries and groups run their own satellite systems, and most modern receivers listen to several at once. The general name for all of them is GNSS, global navigation satellite system.
A short history of GPS
The U.S. Department of Defense began developing the system in the 1970s for military navigation, and the first test satellite went up in 1978. The full constellation was declared operational in 1995. For years, the signal for civilians was deliberately made less precise; that limit was switched off in 2000, which made the receivers in cars and later in phones far more useful. The system is still run by the U.S. military and is free to use worldwide.
Writing and talking about GPS
- Say it as three letters, "jee pee ess." It is an initialism, and what is an acronym covers that naming detail.
- Keep the capitals and skip periods: GPS.
- "GPS system" repeats the word system, but it is common in speech.
- As a casual verb, "I'll GPS it" means you will look up directions.
For more tech letters, browse the tech acronyms section, including RFID and LTE.
Questions people ask
What is GPS stand for in plain English?
Written out, the GPS full form is Global Positioning System. It refers to the U.S. satellite network and, loosely, to any device that uses it to find location.
Who owns GPS?
The United States government owns it, and the U.S. military operates it. The civilian signal is free for anyone in the world to use.
Does GPS need internet or cell service?
No. A receiver only listens to satellite signals, so it works without a data plan. Map apps may still need data to download maps or traffic, unless the maps are saved ahead of time.
How many satellites does GPS use?
The system is designed around 24 satellites, and usually around thirty are active so there are spares. A receiver needs signals from at least four for a full position fix.
Is GPS an acronym?
Because people voice each of the three letters, GPS is, strictly, an initialism. In casual talk it is called a GPS acronym, and either label is understood.