The Wide- and Local-Area Combined GNSS Real-Time Precise Positioning Service System and Products

With the development of Global Navigation Satellite System (GNSS), Multi-GNSS combined real-time precision positioning has become the current trend of GNSS application. Though every navigation system can provide the Standard Point Positioning (SPP) service, it is limited to the low precise navigation because of the low accuracy. The external precise orbit and clock correction is necessary to improve the positioning accuracy. Based on the super-fast precise orbit product of Wuhan University, we estimate the precise orbit and clock correction for GPS, GLONASS, BDS and Galileo system, which can support the wide-area precise positioning. For the local-area users, the real-time service system can provide the FCB and tropospheric and ionospheric delay correction model. All these products are encoded and broadcasted to the precise positioning users via Internet. Users can use these real-time products to correct the orbit and clock error of broadcast ephemeris to improve the SPP precision effectively, or carry out the regular real-time PPP positioning. Meanwhile, given the FCB and atmospheric delay correction products, users can also carry out the PPP-RTK positioning.