An automotive GPS (Global Positioning System) unit is a navigation system in your car made possible by GPS satellites and the signals they send down to a GPS receiver in your car. This GPS system enables the driver of the car to find his way to a certain destination via a route mapped out by the navigation device. The GPS gives you your position according to the coordinates established by satellite feeds, however it is only with the use of a digital map of the streets that the GPS navigator can show you your position in relation to your surroundings.
What this means is that in order to work effectively and to show the driver the best route, the data fed into the GPS has to be as up to date as possible, the content of the data, its format and the type of media used are all important. These three elements are briefly discussed below.
A vector map serves to provide the content for the road database, which paints out the detailed street grid of a particular area from which your car GPS system can calculate your optimum route from point A to point B. Street names and addresses are used as points of reference by which the GPS can orientate itself. With this information in place it becomes possible for the system to guide you directly to your destination. Updates and added information for improving the detail of an area's vector map can be sourced through various means, which will be discussed below, but this information will be of greater help the more detailed the data.
The vector map which enables the functional use of your GPS kit can come in a variety of formats as there is no industry standard to ensure that all maps will are of one uniform format. Although Tele Atlas and NAVTEQ are producers of a standardised map format, the individual navigation system companies who manufacture the GPS units may alter things according to their specific liking, differentiating the formats and ensuring selective compatibility.
The media (means of storing information) used by the GPS to store or upload data can differ from unit to unit. A vector map or street database can be loaded and stored in ROM, or on CD, DVD, hard disk or flash disk. Sometimes there is a combination of these devices. Mostly ROM is used for the foundation of the map, while a second medium is used to add in the details of a specific area. The ROM is normally programmed by the manufacturer, while the downloading of further details through other media can be easily and directly done by a card reader, blue tooth GPS connection or through a computer.
Information on GPS in your car!