Integration of GNSS observations with volunteered geographic information for improved navigation performance

Abstract

Pedestrian and vehicular navigation relies mainly on Global Navigation Satellite System (GNSS). Even if different navigation systems are integrated, GNSS positioning remains the core of any navigation process as it is the only system capable of providing independent solutions. However, in harsh environments, especially urban ones, GNSS signals are confronted by many obstructions causing the satellite signals to reach the receivers through reflected paths. These No-Line of Sight (NLOS) signals can affect the positioning accuracy significantly. This contribution proposes a new algorithm to detect and exclude these NLOS signals using 3D building models constructed from Volunteered Geographic Information (VGI). OpenStreetMap (OSM) and Google Earth (GE) data are combined to build the 3D models incorporated with GNSS signals in the algorithm. Real field data are used for testing and validation of the presented algorithm and strategy. The accuracy improvement, after exclusion of the NLOS signals, is evaluated employing phase-smoothed code observations. The results show that applying the proposed algorithm can improve the horizontal positioning accuracy remarkably. This improvement reaches 10.72 m, and the Root Mean Square Error (RMSE) drops by 1.64 m (46 % improvement) throughout the epochs with detected NLOS satellites. In addition, the improvement is analyzed in the Along-Track (AT) and Cross-Track (CT) directions. It reaches 6.89 m in the AT direction with a drop of 1.076 m in the RMSE value, while it reaches 8.64 m with a drop of 1.239 m in the RMSE value in the CT direction.

Construction and Application of Three-dimensional Information Management System for Intelligent Buildings Integrating BIM and GIS Technologies

“…GIS has advantages in this area, as it takes the geospatial data of the whole earth as an object and performs a series of technical operations on it [20] GIS is now widely used in the field of exterior spatial planning and location selection of buildings. The integration of 3D BIM models with GIS platforms not only enriches the macro to micro building information, but also effectively deals with the problem of information silos from micro to macro [6,9] The integration of both data can give full play to their respective strengths and make up for their weaknesses to achieve a more complete 3D model of the building and its surroundings. By combining BIM and GIS technologies, the 3D building IM system enables intelligent buildings to manage and maintain projects throughout their lifecycle.…”