Maps displays your location on the map using GPS, A-GPS, or cell ID based positioning.
The Global Positioning System (GPS) is a satellite-based navigation system used for calculating your location. Assisted GPS (A-GPS) is a network service that sends you GPS data, improving the speed and accuracy of the positioning.
With cell ID based positioning, the position is determined through the antenna tower your cellular phone is currently connected to.
When you use Maps for the first time, you are prompted to define the internet access point to use to download map information or use A-GPS.
The Global Positioning System (GPS) is operated by the government of the United States, which is solely responsible for its accuracy and maintenance. The accuracy of location data can be affected by adjustments to GPS satellites made by the United States government and is subject to change with the United States Department of Defense civil GPS policy and the Federal Radionavigation Plan. Accuracy can also be affected by poor satellite geometry. Availability and quality of GPS signals may be affected by your location, buildings, natural obstacles, and weather conditions. GPS signals may not be available inside buildings or underground and may be impaired by materials such as concrete and metal.
GPS should not be used for precise location measurement, and you should never rely solely on location data from the GPS receiver and cellular radio networks for positioning or navigation.
The trip meter has limited accuracy, and rounding errors may occur. Accuracy can also be affected by availability and quality of GPS signals.