Abstract
Japan has developed QZSS, and operations will be started with four satellites from fiscal 2018. In this study, we verified the improvement effect of the positioning accuracy by using GPS and three "MICHIBIKI" on quasi-zenith satellite orbit (QZO). We conducted a 24 hours observation experiment in different surrounding environment and compared them. As a result, it was confirmed that the positioning accuracy was most improved especially in vertical direction when using GPS and three QZSS. When using three QZSS, one or more satellites always exists at an elevation angle over 70°. And, QZSS are especially effective on places where influence of the obstructions is large, because QZSS near the zenith are less susceptible to shields.
