Authors: Shenping QIU, Yifan XI, HaoWANG, Lei YE
Nowadays, a number of GNSS system are available, GPS, GLONASS, Beidou, Galileo, and many other regional GNSS systems. However, because of measurement error, especially the multipath effect, the usefulness of these systems in very dense urban areas such as Hong Kong could be limited. In this paper, positioning performance of GNSS has been investigated based on theoretical analysis and numerical studies. Firstly, various field tests have been conducted, include: a) Positioning test with professional GNSS receiver which can observe GPS, GLONASS, Beidou signal in urban area; b) Positioning test with professional GNSS receiver which can observe GPS, GLONASS, Beidou signal in open area; What’s more, a specialized GNSS performance comparison system has been developed to analyze GNSS data, functions of the system mainly include: data visualization function to display positioning results on a map, statistical analysis function to do various analysis on indicators and display the results with charts, and other basic functions. With the help of the system, the comparison work was conducted. Several conclusions have been drawn: the multiple GNSS can improve coverage in urban area obviously; both in urban and open area, the multiple GNSS improve the positioning accuracy slightly; DGNSS can improve the accuracy much and keep the positioning results in a high accurate level both in open and urban areas. Therefore, we can get further conclusion that multiple GNSS and DGNSS can efficiently reduce the multipath effect and spatially correlated error respectively, and then improve the positioning performance significantly.
Keywords: Multiple GNSS, DGNSS, Performance, Urban area, Visualization, System Development.