GIS Simulation for Estimating Satellite Visibility and Positioning Accuracy in an Integrated GNSS Environment

摘要

This paper describes a GIS (Geographic Information System) simulation to predict the improvement of satellite visibility and positioning accuracy in an integrated GNSS (Global Navigation Satellite System) environment. Our simulation deals with the upcoming integration of GPS (Global Positioning System), Galileo, and QZSS (Quasi- Zenith Satellites System). We develop a method called SPROC (Satellite’s Participation Ratio in Outliers vs. in Cluster) for the accuracy improvement by multipath mitigation. The SPROC method discovers a spatial distribution pattern from the simulated positions derived by all combinations of visible satellites. In the integrated GNSS environment with elevated satellite visibility, spatial outliers mean noise-like measurements generated by multipath-producing satellites, and a spatial cluster denotes a concentration area formed by multipath-free satellites. We identify multipath-producing satellites for a given location and time, using the ratio of the participation in spatial outliers versus in a spatial cluster for each visible satellite. For accuracy improvement, the multipath-producing satellites identified by SPROC are excluded in position computation. An experiment of a skyscraper area in Shinjuku, Tokyo demonstrates the remarkable accuracy improvement by SPROC