How GPS Works in Cars

Features

For those of us who are "directionally-impaired", a GPS device can go a long way towards simplifying everyday life. Also known as a "global positioning system", this technology is now included within a number of newer model cars. This is made possible through a receiver antenna on a car that communicates with satellites in space. Its main purpose is to let you know where you are, and how to get to your destination.

In addition to providing directions, GPS locators track vehicle mileage and speed, keep a record of your driving activity and track distance traveled. The more sophisticated devices can alert you when your car is stolen, and even let you know when your speeding. Car manufacturers that include this technology in their vehicles are Ford, BMW, General Motors and Lexus.

Function

Global Positioning Systems work off of a network of satellites that orbit the earth on a continual basis. The satellites act as locator devices that pass information back and forth with a car's antenna. Whenever a driver activates her GPS device, three satellites work together to locate the car using signals meant to narrow down the area and location. A fourth satellite analyzes the data generated from the other three to pinpoint a car's exact location.

The mapping interface inside the car is generated by information received from the satellites. Based on longitude and latitude calculations, the location of the car is indicated by an arrow-shaped icon on the console screen. The information that goes into the map is compiled by specialty map-making companies. GPS manufacturers purchase these map databases for inclusion in their navigational systems.

Differential GPS

Most GPS devices have a touch-screen display where the driver enters in his desired destination. The better the system, the more user-friendly this display will be. The display maps are based on real-word surveying, and data compiled from government sources with satellite imagery. When first using the system, users have to program the system for use with their vehicle. Once set-up, just enter a destination address on a touch screen using an onscreen keyboard.

The system relays direction information through a built-in speaker console as you drive. This voice automated feature can be turned on or off at your discretion. The map display can be set up to show close-up diagrams of each intersection as you progress towards your destination. Arrows on the diagram indicate which direction to turn. The more sophisticated systems display city attractions like hotels and restaurants, as well as provide alternate routes to destinations.