In a very precise orbit, GPS satellites take two revolutions around the Earth in a day. A unique signal and an orbital parameter are transmitted by each satellite. Through this, the GPS device decodes and locates the correct location of the satellites. Through this information and trilateration, GPS detects the exact location of the users. The distance to each satellite can be measured through the GPS system. It is measured as per the time a satellite takes to receive the transmitted signal.
To track your movement and get 2D position, a GPS receiver needs to be locked at least onto 3 satellites. By connecting to the 4 or more satellites, your 3D position can also be determined. Usually, the GPS receiver connects with more than 8 satellites, but it is dependent on your location and the time of the day. There are many devices that can do all this from your wrist.
After determining the position of the user, the GPS unit can calculate the other informations like:
- Distance to the destination
- Trip distance
- Sunrise and sunset time