source:truck tracking webfleet solutions release time:2022-12-29 Hits: Popular:realtime gps tracker online
The users of the GPS system are very invisible. It is a one-way system, and users only receive signals without transmitting them. Therefore, the number of users is unlimited. Although the GPS system was built for military purposes at the beginning, it has been rapidly developed in civilian areas, and various GPS receivers and processing software have emerged. At present, the receivers appearing in the Chinese market mainly include NovAtel, ASHTECH, TRIMBLE, CMC, etc. The receiver that can observe two frequencies is called dual frequency receiver. The receiver that can only observe one frequency becomes single frequency receiver. They are quite different in accuracy and price.
For users in the surveying and mapping field, GPS has caused revolutionary changes in the field of surveying and mapping. At present, the control network or deformation monitoring network covering several kilometers to thousands of kilometers, with positioning accuracy ranging from hundreds of meters to millimeters, generally use GPS as the preferred means. With the maturity of RTK technology, GPS has begun to penetrate into decimeter and even centimeter level lofting, high-precision dynamic positioning and other fields.
Since 1992, IGS, an international GPS geodetic and geodynamic service, has established multiple data storage and processing centers and more than 100 perennial observation stations around the world. China has also set up a number of perennial observation stations in Shanghai Yushan, Wuhan, Xi'an, Lhasa, Taiwan, etc. The observation data of these stations are transmitted to the data storage center in the United States every day through the Internet. IGS also integrates the results of each data processing center almost in real time, And participate in the global coordinate reference system maintenance of the international earth rotation service IERS and the release of the earth rotation parameters. Users can also obtain observation data, precise ephemeris and other products from INTERNET for free.
The real-time navigation and positioning accuracy of the GPS system is very high. The United States has implemented the so-called SA policy since 1992, that is, to reduce the accuracy of satellite positions in broadcast ephemeris, to reduce the accuracy of clock correction numbers, to add high-frequency jitter to the satellite reference frequency (reducing the measurement accuracy of pseudo range and phase), and then to implement the A-S policy, that is, to change the P code to Y code, which further restricts the precision pseudo range measurement, The US military and licensed users are not affected by these policies, but in order to obtain greater commercial benefits, these policies will eventually be cancelled.
Read recommendations:
Last article:Origin of GPS development
Next article:GPS navigation satellite has a high-precision atomic clock for time service
Related Information
portable gps tracker wholesaler
2023-03-16gps tracker no monthly fee
2023-04-11OBD GPS Tracker
2023-03-16Gps speed limiter manufacture
2023-04-23Car gps tracking Processing
2023-04-23mini gps tracker distributors
2023-04-23GPS Tracking
2023-04-11real-time gps tracking sales
2023-04-234G GPS Tracker for vehicles
2023-03-16GPS Tracker wholesaler
2023-04-11TK103B
2022-06-20G900LS 8 Lines-4G Car GPS Tracker
2025-03-31G900LM-4G Car Mini GPS Tracker
2025-03-25G900LM-4G Car GPS Tracker
2025-03-25YG119- Hunting Dog GPS tracker
2023-10-07GPS tracker brings boon to bird conservation
2022-09-17Advantages of GPS technology
2022-10-22Classification of GPS antenna
2022-11-12Actual demand and development trend of GPS market
2022-12-22GPS Navigation
2022-08-12Beidou Satellite Positioner Function.metal spring buckle Factory
2023-06-06GPS receiver.gps tracker no monthly fee distributors.gps tracker no monthly fee ufacturer
2023-04-13Recommended Minimum Specific GPS/TRANSIT Data (RMC) GPS recommended positioning information
2022-09-28Car GPS Navigation System Operation
2022-11-04Principles of GPS System.Cantrack TK100
2023-09-04LBS(Galileo) positioning
2022-10-25Enhanced GPS Positioner Dual Camera Controller Interface Description.Car gps tracking
2023-09-23GPS pseudo-range difference principle
2022-10-11Advantages of GPS technology
2022-10-22How to measure radar, GPS, Beidou and radio positioning.gps tracker for trailer Processing
2023-05-12