Abstract In order to study the effect of GPS/BDS combined orbit determination(OD) on Beidou navigation satellite system(BDS) orbits in different cases, GPS/BDS combined and BDS-only OD experiments are conducted respectively, adopting different lengths of OD arc and different distributions of ground tracking network. Precision and accuracy of OD results of these two methods are compared thoroughly by orbit overlapping arc difference, difference with MGEX products and satellite laser ranging(SLR) residuals. The results show that, with the regional tracking network, GPS/BDS combined OD can noticeably improve the precision and accuracy of BDS IGSO/MEO satellite orbits for 1-day solution but only have marginal improvement on that of all types of BDS satellite orbits for 3-day solution. With the global tracking network, combined OD can improve the precision in along-track and cross-track directions of BDS IGSO/MEO satellite orbits for both 1-day and 3-day solutions but have minimal improvement on the accuracy in radial direction. Furthermore, combined OD barely has an effect on the precision and accuracy in all directions of BDS GEO satellite orbits.
