Analysis of GNSS Performance Index Using Feature Points of Sky-View Image

When sky-view factor (SVF) is used to predict the positioning performance of the global navigation satellite system (GNSS), it is easy to use the SVF as a performance index without a specific database, as it is used for topographic maps, not only in an open-sky land but also in regions where there are many tall buildings. However, conventional SVF is only able to express the degree of openness of the sky as a ratio, and it is limited to being used as a performance index for the positioning that uses the GNSS. When the conventional SVF is used in a land transportation environment, the predicted value for the positioning performance of the GNSS is often not consistent with the actual positioning error, but when sky-view-based dilution of precision (SVDOP) is applied, we confirmed that it was substantially close to the actual positioning error. This confirms our expectation that the utilization of the proposed method rather than the utilization of SVF alone in land transportation environments will make the analysis easier. In this paper, the SVDOP is calculated with real Global Positioning System data, and its usefulness is validated by comparing it with the conventional SVF and the DOP.