一种基于OpenMP的高效GPS卫星钟差实时估计方法

摘要

In this paper,a single observation Kalman filter is proposed to speed up the gain matrix computation.The OpenMP technique is introduced to accelerate the covariance matrix update.Lastly,55 reference stations are selected to estimate real time GPS satellite clocks from day 79 to day 89 in 2017.The estimated clocks are compared with IGS final 30 s clocks.PPP in static and kinematic solutions for 10 stations are carried out.The results show that the differences are within 0.5 ns,the precision in horizontal can be better than 1 cm in static and 1～2 cm in kinematic.The precision in vertical can reach up to 1.5～3 cm in static and range from 3～4 cm in kinematic.Furthermore,the time cost for each epoch is reduced to 4 s from 6 s when 8 slave threads are involved.%提出基于单观测值的Kalman滤波快速计算方法,并引入共享存储并行编程(OpenMP)技术实现协方差快速更新,从而实现非差GPS卫星钟差的快速实时计算.均匀选取55个IGS参考站,计算2017-03-20～03-30采样率为60 s的卫星钟差.与IGS事后30 s钟差相比,两者具有很好的一致性,RMS互差优于0.5ns.选取未参与钟差解算的10个IGS参考站进行精密单点定位,结果表明,实时静态PPP水平方向精度优于2 cm,高程方向精度为2～4 cm;实时动态PPP水平方向精度为2～4 cm,高程方向精度为4～6 cm,能够满足实时PPP的精度要求.该方法在主频1.2 GHz服务器上8线程并行模式下单历元耗时4s,相比串行模式效率提升1/3.