TY - JOUR A1 - Tu, Rui A1 - Ge, Maorong A1 - Zhang, Hongping A1 - Huang, Guanwen T1 - The realization and convergence analysis of combined PPP based on raw observation JF - Advances in space research N2 - In order to speed up Precise Point Positioning (PPP)'s convergence, a combined PPP method with GPS and GLONASS which is based on using raw observations is proposed, and the positioning results and convergence time have been compared with that of single system. The ionospheric delays and receiver's Differential Code Bias (DCB) corrections are estimated as unknown parameters in this method. The numerical results show that the combined PPP has not caused significant impacts on the final solutions, but it greatly improved Position Dilution of Precision (PDOP) and convergence speed and enhanced the reliability of the solution. Meanwhile, the convergence speed is greatly influenced by the receiver's DCB, positioning results in horizontal which are better than 10 cm can be realized within 10 min. In addition, the ionosphere and DCB products can be provided with high precision. KW - GPS and GLONASS KW - Precise Point Positioning KW - Raw observation KW - DCB KW - Combine Y1 - 2013 U6 - https://doi.org/10.1016/j.asr.2013.03.005 SN - 0273-1177 VL - 52 IS - 1 SP - 211 EP - 221 PB - Elsevier CY - Oxford ER -