Objectives  The BeiDou global navigation satellite system (BDS-3), which provides high-accuracy positioning, navigation and timing (PNT) services to global users, has completed the construction in 2020.

  Methods  To analyze the performance of BDS-3, the total number of visible satellites of BDS-3 preliminary system and BDS-2 over the 'Belt and Road' area is calculated by using a method based on satellite distribution probability, then the satellite visibility of the full constellation BDS-3 over the global areas is also estimated with the same method. In addition, the dilution of precision (DOP) and their differences between BDS-3 and BDS-2 for stations at different geographical locations are investigated.

  Results  Results indicate that, over the 'Belt and Road' area, the total number of visible BDS-3 preliminary system and BDS-2 satellites is 8-20, and the geometrical DOP (GDOP) is less than 1.85.In China and its surrounding areas, the visible number is more than 16, the GDOP is between 1.3 and 1.4. For the full constellation BDS-3-only, the number of visible satellite is 7-15 over the global areas. The total number of visible full constellation BDS-3 geostationary earth orbit satellites and inclined geosynchronous orbit satellites is less than that of BDS-2, but for medium earth orbit satellites, the number of visible satellites of the former system is more than that of the latter system by 6-8. With a better satellite visibility, the average BDS-3 position DOP, horizontal DOP, vertical DOP and time DOP are 1.356, 0.759, 1.123 and 0.682 over China and its surrounding areas, respectively, which are 22.6%, 28.8%, 19.2% and 37.0% lower than those of BDS-2, and have 4%-13% improvement compared to the global DOP averages.

  Conclusions  Compare to the BDS-2, BDS-3 satellite visibility has been improved significantly, while it will provide higher accuracy and more reliable PNT services to global users for its better satellite constellation.