How Your Phone’s GPS Really Works
The Global Positioning System (GPS) is a radio-navigation system composed of twenty-four satellites and their corresponding ground stations. GPS emits satellite signals, which are processed by a GPS receiver. Location is determined by the velocity and timing of the intercepted satellite signal.
A GPS tracking system can be placed inside a phone, vehicle or other unit to track movement and provide location information. By using the Global Navigation Satellite System (GNSS) network, a GPS tracking system can facilitate directions and other services.
Many GPS-empowered mobile applications are optimized to work offline. GPS devices, including mobile smartphones, have a GPS receiver and an offline map database so that locations are accessible without an Internet connection. Cached navigation and directions will be available once your device no longer has a connection.
However, a handful of apps offer enhanced location services with offline map support. The apps use your mobile device’s built-in GPS radio (which does not affect your data plan) to figure out your location and map a route that’s stored in your phone.
Free offline GPS navigation apps for Android include Osmand and Navfree. Google maps save offline map data on an iPhone or iPad, but don’t offer offline navigation. The following applications are a little more costly, but represent a few of the multiple offline GPS systems in the market: Navmii, Sygic GPS Navigation and Navigon.
GPS signal is available offline because it operates independent of cellular networks and Internet signals. This capability also enables location services within GoSpotCheck to function without Internet signal – either WiFi or a cellular connection.