What is GPS?

Written by Michelle McGrath.

Last updated about 1 month ago.

GPS or Global Positioning System is a satellite navigation system developed by the United States Department of Defense. The GPS system incorporates 24 satellites that orbit the earth and transmit signals to GPS receivers on the ground. A GPS receiver uses signals from multiple satellites to determine its location, speed, direction and time.

GPS receivers have been used for defense, maritime and many industrial applications. Consumers are benefiting from cheaper GPS receivers for navigation. Lower cost GPS devices have become available integrated into mobile phones, as lower cost hand held units and as portable or integrated in-car systems.

Types of GPS - handheld, car and maritime

Handheld GPS

Personal handheld GPS devices have been highly recommended for bushwalkers and intrepid travelers for years. GPS receivers are now integrated into a number of mobile phones / PDAs and are easily available. It is not practical (and probably illegal in your state) to use handheld GPS devices while driving a car.

Car GPS

In car GPS navigators are either integrated into the dash or portable devices temporarily secured in the car. Integrated GPS devices have the advantages of bigger screens and better integration with the other electronic devices in the vehicle. Portable devices have the advantage of being able to be swopped between multiple cars and offering the ability to program, customize or update the car GPS from the comfort of your house rather than out in the car.

Maritime GPS

These are GPS devices dedicated for use on boats and other maritime transportation. Often they are integrated with other electronic devices such as depth sounders.