The composition of Jiangmen car navigation system:
1, the space part
The space part of Jiangmen Car Navigation System is composed of 24 satellites (21 operational satellites and 3 spare satellites). It is located 20200km above the surface and evenly distributed on 6 trajectories (4 per track surface). The track inclination is 55°. The distribution of satellites allows for the observation of more than four satellites anywhere in the world, at any time, and the navigation information pre-stored in the satellites. GPS satellites, due to problems such as atmospheric conflicts, will gradually decrease in navigation accuracy as time passes.
2. Ground control system
The ground control system consists of a monitoring station (Monitor Station), a main control station (Master Monitor Station), and a ground antenna (Ground Antenna). The main control station is located in Colorado Spring, Colorado, USA. The ground control station is responsible for collecting the information returned by the satellite and accounting for satellite ephemeris, relative spacing, atmospheric proofreading and other data.
3. User equipment part
The GPS vehicle receiver has a built-in GPS satellite receiver module for receiving satellite navigation message information, and records the vehicle condition information with other external data sensors and devices, and then processes the message into a message through the GSM/CDMA network to GPRS. Transmission methods such as /CDMAD are sent to the monitoring center via the Internet. The monitoring center is parsed and stored in the system database by the series of software programs equipped, and the vehicle position information is displayed through the electronic map, thus reaching the purpose of visual monitoring.
A monitoring center can send instructions such as voice or text to the vehicle terminal and related connecting devices (such as electronic screens) through the system. On this basis, the system also provides various customized processing reports (alarm log accounting report, distance accounting report, etc.) for the use and practice of the industry, in order to improve the operational efficiency of mobile and other mobile policies, and ensure safe operation and operation. Improve the quality of integrated services and improve the level of scientific management.
Car navigation brand
Car gps locator operating principle:
The operation principle of the GPS positioning system is to collect the observation materials and meteorological information of each monitoring station by the ground control station, calculate the ephemeris and satellite clock correction numbers of each satellite, edit the navigation message according to the specified pattern, and pass the injection station on the ground. GPS satellites inject this information.
The mission of the GPS signal receiver is to capture the signals of the satellites to be tested selected according to the fixed satellite altitude cut-off angle, and track the operation of these satellites, and transform, amplify and process the received GPS signals to measure The GPS signal is transmitted from the satellite to the receiver antenna, and the navigation message sent by the GPS satellite is interpreted, and the three-dimensional orientation, orientation, and even the three-dimensional velocity and time of the station are verified in real time.
Car GPS manufacturers show material positioning methods, GPS positioning is divided into single point positioning and relative positioning (differential positioning). Single-point positioning is a method of confirming the orientation of the receiver based on the observation data of a receiver. It can only be measured by pseudo-range observation, and can be used for rough navigation and positioning of vehicles and ships. Relative positioning (differential positioning) is a method for confirming the relative azimuth between observation points based on the observation data of two or more receivers. It can be selected either by pseudo-range measurement or phase observation. Geodetic measurement or engineering measurement should be performed. Phase observations are used for relative positioning.
When measuring positioning, the user can use the receiver's stored ephemeris to get the approximate orientation of each satellite. Based on these data and their own orientation, the aircraft selects four satellites with larger angles between the satellite and the user's line as the observation policy.
In the positioning observation, the receiver uses the information generated by the code attacker to perform correlation processing with the signal received by the satellite, and measures the pseudorange between the user and the satellite according to the time stamp of the navigation message and the subframe count. By correcting the pseudorange and the initial data of the input and the observations of the four satellites, three observation equations are listed, and the orientation of the receiver can be solved, and the required coordinate system is converted to achieve the positioning purpose.
GPS positioning system is also known as GPRS. In short, the GPS positioning system relies on a mobile phone card built in your car terminal. After the mobile phone signal is transmitted to the background to complete the positioning, the GPS terminal is the background, which can help you complete a key. Navigation, background services, and other human services. The GPS positioning system has been used in more and more industries following the development of the society. It has played the role of pre-supervision, post-processing, unified distribution, easy handling, improving our operational efficiency and reducing costs.
Car gps locator effect:
1. Vehicle tracking function The GPS and electronic map can display the actual position of the vehicle in real time, and can be arbitrarily enlarged, reduced, restored, and changed. It can be moved with the policy, so that the policy is always on the screen; Multi-vehicle, multi-screen tracking together. Use this feature to track important vehicles and cargo.
2. Supply road planning and navigation functions Supply road planning is an important auxiliary function of the car navigation system, which includes active line planning and manual line planning. The active route planning is to confirm the starting point and destination by the driver. The computer software actively plans the best driving road according to the requirements, including the fastest road, the simplest road, and the accounting of the road with the least number of highway sections. Manual route planning is based on the driver's planning of the starting point, the end point and the waypoint, etc., to actively establish the road library. After the route planning is completed, the display device can display the planned road on the electronic map, and together show the way of running the car and the operation method.
3. The information query function provides users with primary objects, such as tourist attractions, hotels, hospitals and other databases, and users can display their orientation on the electronic map. Together, the monitoring center can use the monitoring console to query the orientation of any policy within the area, and the vehicle information will be displayed in digital form on the electronic map of the control center.
4. The traffic command function command center can monitor the running status of the vehicles in the area and make reasonable dispatch of the monitored vehicles. The command center can also talk to the tracked policy at any time and implement it.
5. Urgent help function After the GPS positioning and monitoring system, it can help the vehicles in danger or accidents. The electronic map of the monitoring station shows the help information and alarm policy, plans the optimal help plan, and reminds the on-duty personnel to carry out emergency treatment with the alarm sound and light.
