GPS is a brief referusion of Global Positioning System, that is, the global satellite positioning system. In addition to the United States, there are Russia, the EU Global Positioning System, and our usual GPS refers to the US Global Satellite Positioning System. It can accurately measure the instantaneous position of the object at any location by accepting the navigation signals emitted in 24 satellites in the 24 satellites, which can be accurately measured at any location, exactly the latitude and longitude, speed, etc. of the object. information. GPS was originally only used in military fields. At present, GPS has been widely used in the transportation industry. It uses GPS positioning technology to combine wireless communication technology (GSM or CDMA), geographic information management system (GIS) and other high-tech, realize the monitoring of vehicles, digital channels of the GSM network, Transferring the signal to the vehicle monitoring center, the monitoring center is converted by the differential technology, and then the position signal is displayed by the landmap language by GIS, it can eventually achieve the positioning navigation, anti-theft anti-robbery, service rescue, remote monitoring of the vehicle through the service center. Track recording and other functions.
GPS is a star base radio navigation system developed by the US Department of Defense. GPS provides three-dimensional position, speed and time for Global Land, Sea, and empty users 24 hours a day. It is higher than other radio navigation systems.
GPS consists of three parts: spatial segments, control sections, and user segments.
The spatial segment consists of 24 satellites distributed on 6 tracks. Satellite track height 20,200 km, tilt angle 55 degrees, period of 12 hours. Satellite track distribution ensures at least 6 satellites at any time in the world. Satellite continuously provides location and time information to users.
The control section consists of a master station, 5 monitoring stations, and three injection stations. The master station is located in Colorado. Monitoring Station tracks all GPS satellites in the field of view, collecting satellite ranging information, and sending the collected information to the main station. The master calculates the satellite precision orbit and produces navigation information for each satellite, and is transferred to the satellite by the injection station.
The user segment consists of the receiver, processor, and antenna. The location speed and time of the user are calculated by receiving satellite broadcast information.
The concept of GPS is based on satellite ranging. The user calculates its position by measuring their distance to the satellite. The location of the satellite is a known value. Each GPS satellite sends a position and time signal. The user receiver measurement signal arrives at the time delay of the receiver, which is equivalent to measuring the distance of the user to the satellite. At the same time, four satellites can solve the location, speed and time.
