BDS-3/GNSS Data Quality and Positioning Performance Analysis

Since November 2017, China has launched 24 Beidou-3 (BDS-3) navigation satellites. So far, China’s independently developed Beidou satellite navigation system has officially entered the global service stage. Compared with the Beidou-2 satellite navigation system (BDS-2), the MEO satellite of the Beidou-3 satellite navigation system (BDS-3) adds two new signals, B1C and B2a. The quality of the original observation data can directly affect the navigation and positioning system. Positioning accuracy and service performance. This paper selects the original 182-day raw observation data of 23 tracking stations of the International GNSS Monitoring and Assessment System (iGMAS), and analyzes the data quality from four aspects: data integrity rate, signal-noise ratio, cycle slip ratio and multipath effect. The quality of the observed data of GLONASS and GALILEO is compared, and finally combined with the point positioning accuracy of each system for comprehensive evaluation. The results show that in terms of data integrity rate, the data integrity rate of BDS-3 is comparable to that of GPS, GLONASS and GALILEO, and can reach more than 80%. In terms of signal-to-noise ratio, the new BDS-3 satellite The signal strengths of the signals B1C and B2a are not much different from those of the old signals. Compared with other systems, the signal strength of the new BDS signals is better. In terms of the cycle-to-hop ratio, the cycle-bounce ratio of the new signal B2a of the BDS is higher than that of other signals. High, and superior to GPS and GLONASS, it is equivalent to GALILEO’s E5b signal; in terms of multipath effect, the multipath RMS value of each signal of the four systems is within 0.5 m, and the multipath error of BDS-3 satellite B2a signal is slightly the multipath error below B1I and B3I is about 0.1 m. In terms of pseudo-single point positioning and precise single-point positioning, the BDS-3 has a slightly lower positioning accuracy than GPS and GALILEO, but is superior to GLONASS. The results of this paper have certain reference value for the location and maintenance of iGMAS observatory, GNSS data processing and product generation, the development of Beidou GNSS receiver and the positioning performance of Beidou satellite navigation system.