四元数卫星姿态产品对BDS PPP的影响

Influence of Quaternion Satellite Attitude Products on BDS PPP

对比不同分析中心发布的BDS姿态模型的差异发现,卫星机动时期不同分析中心发布的卫星偏航角差异可达近180°。进一步对比四元数姿态、模型姿态、名义姿态3种姿态策略对精密单点定位(PPP)中相位缠绕改正及最终定位结果的影响,结果表明,不同的姿态处理模型会带来近1周的相位缠绕改正差异,使用四元数姿态的仿动态PPP定位结果较名义姿态E、N、U方向的RMS分别减小17%、25%、34%,较模型姿态E、N、U方向的RMS分别减小11%、7%、7%。保持分析中心产品的一致性可以提高PPP精度。

We compare the difference of BDS attitude models published by different analysis centers, and find that the difference of the yaw angle can be nearly 180° at noon and earth shadow time. Furthermore, we compare the effects of three attitude strategies, namely quaternion attitude, model attitude and nominal attitude, on the phase wind-up correction and the final positioning results of precise point positioning(PPP). The results show that different attitude processing models will bring phase wind-up correction difference of nearly 1 cycle. Compared with the nominal attitude RMS, the PPP positioning results of quaternion attitude decreased by 17%, 25%, 34%, respectively, and compared with the model attitude RMS, decreased by 11%, 7%, 7%, respectively. Keeping the consistency of products of the analysis center can improve the precision of PPP.