1. Chen, C., Chang, G.B.: PPPLib: an open-source software for precise point positioning using GPS, BeiDou, Galileo, GLONASS, and QZSS with multi-frequency observations. GPS Solutions 25(1) (2021)
2. He, Y.X., Li, H.J., Zhou, J.: Comparatively analysis of PPP results for products of different IGS analysis centers. J. Navig. Positioning 8(1), 38–42 (2020)
3. Cheng, C., Zhao, Y.X., Li, L., et al.: Performance evaluation of real time and final precision ephemeris products of BDS. In: China Satellite Navigation Conference (2018)
4. Chen, L., Song, W., Yi, W., Shi, C., Lou, Y., Guo, H.: Research on a method of real-time combination of precise GPS clock corrections. GPS Solutions 21(1), 187–195 (2017). https://doi.org/10.1007/s10291-016-0515-3
5. Liu, Y.Y., Ye, S.R., Jiang, P., et al.: Investigation to discontinuity in the IGS final ephemeris and corresponding treatment. Geomatics Inf. Sci. Wuhan Univ. 39(10), 1174–1178 (2014)