抄録
It is expected that the use of GNSS technology in urban areas will be increased. Since there are many buildings in urban areas, the direct signal from satellite occasionally can be reflected or diffracted. As a result, we are faced with big errors due to multipath. It is strongly required to improve reliability considering the use of GNSS for future ITS. In order to do that, the ability to detect the inferior observations of GNSS is required. The objective of this paper is to improve reliability and availability in RTK-GPS. Firstly, this study reveals the relationships between reliability and availability according to the quality check of GPS observation data. For example, reliability decreases when the measurement calculation is done with four numbers of satellites compared with five numbers or more of satellites. Then the detection algorithm to remove the inferior observations of GPS is proposed. The performance was checked by using raw GPS data obtained in major cities and it is confirmed that the performance was improved by using our proposed method.
