Comparison of BDS-3 Satellite Attitude Quaternions Products from Different Analysis Centers and Their Application to PPP

Objectives The satellite attitude quaternion products have been proposed by International GNSS Service in the third data reprocessing campaign (repro3). These satellite attitude quaternion products are not only contributed to combining the precise satellite products during the eclipse season, but also can improve the reliability of precision point positioning (PPP) when satellites are in abnormal yaw attitude.

Methods The four final and rapid BeiDou-3 satellite navigation system (BDS-3) satellite attitude products provided by Wuhan University (WHU), Geo Forschungs Zentrum and Center for Orbit Determination in Europe have been compared. Attitude model characteristic of BDS-3 with different type from different analysis centers have been also analyzed in the eclipse seasons, and the effect of different satellite model on satellite clock and kinematic PPP have been investigated.

Results The results demonstrate that the BDS-3 yaw angle difference can reach up about 120$°$ from different analysis centers when the sun elevation angle is approximately 0°. In this period, different analysis centers used different attitude models. Furthermore, when the satellite attitude quaternions are used from different analysis centers, the PPP positing accuracy can be improved during the eclipse season. In detail, a significant improvement rate is achieved by using WHU rapid products, compared with nominal attitude strategy, the 3D positioning accuracy of kinematic PPP solutions with satellite attitude quaternions can be improved approximately 18.4%.

Conclusion Although the positioning accuracy of PPP solutions can be improved by using the publicly BDS-3 attitude model, various attitude strategies may be adopted in different analysis centers. Therefore, in order to obtain reliable PPP results, the satellite attitude quaternions should be used.