EMZETT.GPS and satellite navigation
In short: GPS is a satellite system with which receivers determine their position. The umbrella term is GNSS, which also includes Galileo (EU), GLONASS and BeiDou.
In more detail: Several satellites send time signals. The receiver measures how long they took and calculates position and exact time from at least four signals. Phones use several systems at once and supplement them with Wi-Fi and mobile data.
In Depth
- Accuracy: about 3 to 10 m, with extra data (DGPS, RTK) even centimetres.
- Between buildings: Reflections worsen accuracy.
- Privacy: Location data is personal. Apps should only get the permission they need (“only while using”).
- Energy: Constant positioning drains the battery (using lithium-ion batteries properly).
- Time signals: GPS also supplies time for networks and banks.