基于DREAMNET的GPS/BDS/GLONASS多系统网络RTK定位性能分析

随着BDS系统完成亚太地区组网、GLONASS系统再次实现满星座部署以及GPS系统的现代化,多系统集成已逐步成为网络RTK技术的发展趋势。本文结合笔者所在课题组自主研发的网络RTK数据处理系统DREAMNET,对不同卫星系统组合模式下的定位精度进行比较分析。试验结果表明,GPS/BDS/GLONASS网络RTK和GPS/BDS网络RTK的定位精度最高,GPS、BDS单系统网络RTK次之。此外,随着高度角的增加,GPS单系统网络RTK的可用性显著降低,而GPS/BDS/GLONASS网络RTK在高度角为40°时依然可以在99.84%的时间里提供水平精度0.01 m、高程精度0.025 m的定位服务。最后,对15 d的定位结果进行统计,包括不依赖GPS系统的BDS和BDS/GLONASS在内的6种组合方式皆可达到水平0.01 m、高程0.025 m的定位精度,其中GPS/BDS/GLONASS网络RTK则可以得到水平0.006 m、高程0.015 m的定位精度,证明DREAMNET的定位精度和稳定性完全可以满足测绘作业的需要。

Positioning Accuracy Analysis of GPS/BDS/GLONASS Network RTK Based on DREAMNET

With BDS being continually providing service in the Asia-Pacific Region, GLONASS being fully operational with 24 satellites in orbit again and GPS modernization, multi-GNSS network RTK will become the development trend of network RTK in the future. The data of multi-GNSS will be process by data reserving, editing and managing system of network RTK (DREAMNET), which developed independently by this research group, to analyze and compare the positioning accuracy between different combinations of global navigation satellite system. According to the experiment, the positioning accuracy of GPS/BDS/GLONASS network RTK and GPS/BDS network RTK is highest, GPS and BDS only second. Besides, with the increasing of the cut-off elevation, the availability of single GPS network RTK significantly reduces. However with 40°cut-off elevations, positioning service with the accuracy of 0.005m in horizontal, 0.025m in vertical will be provided by GPS/BDS/GLONASS network RTK in 99.84% time of a day. Finally, the statistics of positioning accuracy for 15days show that the accuracy of 0.01m in horizontal, 0.025m in vertical could be reached in six situations, which including BDS and BDS/GLONASS network RTK. Besides, the accuracy of 0.006m in horizontal, 0.015m in vertical could be reached by GPS/BDS/GLONASS network RTK, proving that the positioning accuracy and stability of DREAMNET can meet the needs of surveying and mapping.