亚洲日韩国产精品无码A∨_少妇人妻一级a毛片无码_国产成人一区二区视频在线观看_超级碰碰视频永久免费_免费观看的成人黄色视频_亚洲电影天堂在线国语对白_鲤鱼门直播回放不掩挡_国产91制服丝袜在线无码_成人精品激情无码_台湾中文操逼中出

GPS is the global positioning system. In short, this is a satellite system composed of 24 satellites covering the world. This system can ensure that four satellites can be observed at any point on the earth at any time, so as to ensure that the satellites can collect the longitude, latitude and altitude of the observation point, so as to complete the functions of navigation, positioning, timing and so on. This skill can be used to guide aircraft, ships, vehicles and individuals to arrive on time along the selected route safely and accurately.

Application: Shaanxi GPS has been widely used in aerospace, aviation, sailing, transportation, measurement, exploration, logistics industry, vehicle scheduling, vehicle navigation and many other fields.

　　GSM

The full name is: Global System for mobile communications, and the Chinese name is global mobile communication system, commonly known as & quot; Global communication & quot;, It is a mobile communication skill specification originated in Europe and the second generation of mobile communication skills. Its development intention is to enable all parts of the world to use a mobile phone network specification together, so that users can travel all over the world with a mobile phone. China introduced this skill specification in the early 1990s. Before that, it has been using cellular imitation mobile technology, that is, the first generation GSM Technology (China closed the imitation mobile network on December 31, 2001). At present, China Mobile and China Unicom each have a GSM network, which is the largest mobile communication network in the world. The GSM system includes several frequency bands such as GSM 900:900mhz, gsm1800:1800mhz and gsm-1900:1900mhz.

Application: generally used in remote meter reading, investigation industry, etc.

Principles and differences of GPS and GSM positioning

GPS uses satellite positioning, which requires GPS chip (GPS chip includes RF chip, baseband chip and microprocessor chip set). Generally, it can be positioned only by connecting three satellites.

GSM uses a base station for positioning. In fact, the precise name of GSM is A-GPS positioning. GPS chip is not required. The principle is to confirm the orientation through the adjacent signal base station.

Comparison between the two

GPS needs to find satellite positioning. The search speed depends on factors such as cloud thickness. The first search speed is slow, but it only needs to search the proximity of the satellite. The advantage is that the positioning is accurate, and the general error is about a few meters.

GSM uses the location of the base station to confirm the location, but it can only confirm the approximate location, and needs to connect to the network, which consumes traffic. The positioning error is very large, usually about one or two hundred meters.

Therefore, GPS positioning is generally used, or combined with GSM. Now GPS positioning is generally GPS + GSM positioning.

The article comes from Jiangmen vehicle navigatorhttp://cnjhl.cn