The principles of automotive GPS navigation system is a positioning satellite signal can be received through the microprocessor to calculate the exact longitude and latitude where the car and the car speed and direction, and displayed on the display of a device.

Car ownership in the world increases every year,bringing about a serious road traffic congestion, which became a major environmental hazard, but also caused huge economic losses. Build roads, increase the flow capacity, although an important way to solve traffic congestion, but some roads wind developed countries have the world well aware that highway expansion alone to solve the traffic congestion is very limited,and must seek a high science and technology to the solution – Automotive navigation system.

How to locate the GPS?
GPS system was originally in the military needs for combat troops to provide accurate positioning, such as aircraft, ships, etc., to ensure that the initiative campaign. A few years ago began in the civil promotion, mainly used in navigation, mapping, speed, vehicle theft, and scheduling.
It is through the ground at any point (such as cars) and over the four positioning satellites to calculate the relative distance of the exact location of the car. If we know the distance of a satellite pitch, we can know that the point must be at the center of the sphere to the first satellite, the distance of the sphere radius, if we know the distance from the second satellite of known satellites, we can confirm that point of intersection of two spheres in a circular curve, with the third satellite that we can be before the third sphere and a circular curves intersect at two points, generally the distance through the fourth satellite that we uniquely determine the latitude and longitude of the point.

Status of  car navigation system:
car navigation system development and application in our late start, still in its infancy, the key is used in special vehicles, such as bank armored cars, police patrol cars and so on. But as the Great Wall of police command and GPS Shanghai Dazhong Taxi Co., Ltd. of the opening of GPS scheduling system to use,indicates that China has wider application of vehicle navigation system is no longer distant.
Easy up recently by the Beijing New Technology Development Company and the Chinese Academy of Sciences of automotive experts to develop the satellite orientation device has been officially on the market. It can be any of the dynamic position of the car accurately displayed on the instrument at any time the electronic map. The guide instrument automatically tracks the electronic map shows the current location of vehicles and the surrounding circumstances. This orientation device has the memory of the electronic transport in major urban road map and the national road network and its high accuracy above the level of villages and towns along the names. Driver-oriented instrument at any time on the inquiry in the 300 km radius from the geographical information, to provide a safe and smooth vehicle driving directions. In addition, the driver can also routes the input-oriented instrument at any time, to ensure that the original way back. The instrument is only the size of an ordinary book, weight 600 grams, the use of car cigarette lighter power supply, easy to use.

car navigation system around the world situation:
Some luxury cars in Japan, the navigation system is no longer the option, made to standard equipment. For example, Toyota Windom, Nissan Cina, Honda Legend, In addition, there are some imported cars such as Mercedes-Benz S-Class sedan, BMW’s new 7 Series and 5 Series cars are equipped with such electronic navigation system. Mitsubishi Motors is a bold gamble, as standard equipment, the navigation system installed in the middle on the Galant sedan. As car navigation system extended to more models, so the interior decoration design, the dashboard leaving a 15 cm in advance about the location of the video display screen, has become routine. New cars sold in Japan in 1997, one tenth of the installed navigation system is expected to reach one-third in 2005, including micro-car included. Basic navigation system in Japan, starts at $ 1,300.
Ford’s only car radio size GPS system, it is with radio, telephone sets fit together. Display in the center, and provide the direction for the drivers voice instructions, but does not display the map, via GPS satellite signals to determine the location of cars. Lancaster West Germany (Germany’s largest car rental companies) in 1997 with the procurement of the 8000 Mercedes-Benz car navigation system, eight airports in Germany to provide services. The service system as long as the driver entered the car’s computer to the destination, you can calculate the shortest route, and then on the screen with images and sound to guide the driver to open the destination.

In addition to accurate GPS positioning, there are the following functions:
It can directly enter the names, latitude and longitude, the line phone number to retrieve and quickly provide the best route to a destination; a result of road congestion, road construction or the wrong way and other unforeseen circumstances, the best route is not feasible, the search can then provide a new route; order to advance understanding of the driver driving the changes in the road, it can make the voice prompts, such as general road 500 m before the highway before the driver instructions 1000 m and the change of road conditions direction; vehicle driving in the intersection before crossing the whole real screen can automatically map, specify the name of the intersection, turn after the road name and direction, which is a major automotive navigation capabilities. Can be said that the biggest civilian car navigation system  market is.