Analysis and Modeling of PPP Residuals from GPS and GLONASS

The PPP results are different for the same station at the same time when using different GNSS observations. The reason is that there are some different system errors in every navigation system, such as satellite orbit error, satellite clock error, frequency drift, etc. In this paper, a lot of data from GPS and GLONASS mixed observation stations are processed using CSRS-PPP software. The results show that the positioning precision of GPS is better than that of GLONASS and the positioning precision of the N component is better than those of the E and U component. There are some regular varieties in the residuals, which includes the trend items and periodic items. Therefore, an error compensation model is constructed. The experiment results show that the PPP precision of GPS and GLONASS can be improved by using the proposed model.