Another common feature of mobile devices is the Global Positioning System (GPS). GPS is a navigation system that determines the time and location on Earth using messages from satellites in space and a receiver on Earth. A GPS radio receiver uses at least four satellites to calculate its position based on the messages. GPS is very accurate and can be used under most weather conditions. However, dense foliage, tunnels, and tall buildings can interrupt satellite signals.
There are GPS devices for cars, boats, and hand-held devices used by hikers and backpackers. In mobile devices, GPS receivers have many different uses:
- Navigation - A mapping app that provides turn-by-turn directions to a place, address, or coordinates.
- Geocaching - A mapping app that shows the location of geocaches - hidden containers around the world. Users find them and often sign a log book to show that they found it.
- Geotagging - Embeds location information into a digital object, like a photograph or a video, to record where it was taken.
- Specialized search results - For example, displays results based on proximity, such as restaurants that are close by when searching for the keyword restaurants.
- Device tracking - Locates the device on a map if it is lost or stolen.
To enable GPS on Android devices, as shown in Figure 1, use the following path:
Settings > Location services > Use GPS satellites
To enable GPS on iOS devices, as shown in Figure 2, use the following path:
Settings > Location services > Turn location services on
NOTE: Some Android and iOS devices do not have GPS receivers. These devices use information from Wi-Fi networks and cellular networks, if available, to provide location services.