What is a Global Positioning System?
The Global Positioning System (GPS), developed by the U.S. military, is a globally available system of navigation satellites. It is used for precise location determination as well as time measurement. In logistics and many other fields, GPS has become indispensable:
- Navigation
- Truck position tracking
- Route planning and monitoring
- Geodata collection
- Emergency and rescue services
GPS and Other Navigation Systems
The term GPS is also commonly used to refer to the entire group of existing global navigation satellite systems (GNSS). In addition to GPS, these include the Russian GLONASS system, the European Galileo system, and the Chinese BeiDou system. Modern GPS receivers can combine signals from multiple systems to achieve even more precise results.
How GPS Positioning Works
Each of these systems consists of a network of satellites that send signals to Earth. These signals are received by GPS receivers, which are used in vehicles, mobile phones, or navigation devices. The receivers process these signals to determine not only the current position but also the exact time.
For this system to work, at least four satellites are required. A receiver must be in a location where a sufficient number of satellites in space are “visible.”
To determine latitude, longitude, and altitude, even just three satellite signals are sufficient. This process is known as triangulation. The exact position of the receiver is determined based on the signal travel times from the individual satellites. The fourth satellite is used for accuracy and time synchronization.
Images:
Image: pluie_r / Shutterstock