中文摘要：

本文针对地面用户与空间用户在测量环境与观测几何动态性等方面的不同，基于导航卫星可见性与加权精度因子（WDOP）对混合星座导航系统的定位性能进行了分析。给出了不同用户的星座天空视图与可视时长；从理论上讨论了权值选取对WDOP的影响。仿真表明，地面静态用户对不同类型导航卫星的可见性差异很大；而低轨卫星用户的可视时长更短，观测几何快速变化，WDOP数值较大且呈现周期性变化。

英文摘要：

Aiming at the different features of users on the ground and in the space in the aspects of measurement environment and observation geometry dynamics, the positioning performance of mixed constellation navigation systems was analyzed based on the navi- gation satellite visibility and the weighted dilution of precision （WDOP）. The constellation sky view and visible time intervals were presented. The influence of weight selection on the WDOP was also discussed theoretically. Simulations showed that the static users on the ground possessed an obvious visibility distinction due to the different navigation satellite type. The visible intervals of low-earth-orbiter users were shorter and the observation geometry changed rapidly, while The WDOP of LEO was larger than ground users and showed a periodical feature.