How QZSS contributes to positioning performance in large Asian cities ?

The US GPS and the planed Quasi Zenith Satellite System (QZSS) will enhance the capability of positioning performance. The paper describes numerical analysis of the positioning performance of combined GPS-QZSS system. The performance of general stand-alone positioning in Tokyo is analyzed for different scenarios of the present GPS and combined future GPS-QZSS system. It is also analyzed in the Asian cities of Seoul, Beijing, Shanghai, Singapore and Sydney. The software-based simulator was used for this analysis. This simulator generates everything needed to compute navigation solutions. In order to model the impact of ephemeris errors and atmospheric errors, the real observation data was used. The results indicate that increasing the number of satellites has a benefit on the capability of getting position with high availability.