Abstract：Along with the growth of GNSS, the number of GNSS satellites isalso increasing. The combination of different GNSS satellites could guarantee improved satellite availability. In this paper, unifying multi-GNSS time system is analyzed. Further, a coordinate system and a multi-GNSS single point (SPP) positioning model and a method of determining the weight matrix for multi-GNSS are implemented. The performance of the combined GPS/GLONASS/BDS/Galileo SPP is assessed using the observations from 8 GNSS stations. The position performance is compared between standalone GPS and multi-GNSS with 15°,30°and 45° cut-off elevation angles.The results show that 15° cut-off elevation angle satellite availability is best, and that multi-GNSS advances positioning accuracy only a little. When cut-off elevation angle is 30°or 45°, the satellite availability is worse| standalone GPS is often unable to ensure continuous and accurate positioning due to lack of available satellites, but multi-GNSS still could guarantee the continuity and integrity of real time positioning. In the BDS coverage area, the rate of epochs that can be used for locationis over 95%,and the horizontal direction error is less than 30 m. This paper has reference value for navigation in complex environments, such as an urban environments and thick forests
XU Longwei,LIU Hui,ZHANG Ming et al. Performance Assessment of Multi-GNSS Single Point Positioning
with Different Cut-Off Elevation Angles[J]. jgg, 2015, 35(6): 987-991.
