随机模型在GPS卫星钟差估计中的应用

Application of Stochastic Model in GPS Satellite Clock Estimation

卫星钟差是影响定位精度的重要误差源之一。针对不同接收机评估其伪距观测精度,选择相应的相位观测方差,构建合理的随机模型。采用56个IGS(International GNSS Service)跟踪站观测数据解算卫星钟差,并进行定位验证。结果表明:基于该方法的钟差估计结果与传统的钟差估计方法的结果在定位精度上改进约为5%。使用IGS卫星钟差,将该随机模型用于定位解算,10个测站中,7个测站收敛时间与定位精度有明显改进,收敛时间相较于传统定权方式的解算结果改进最高可达78%、定位精度改进最高可达86.55%。

Satellite clock affects the positioning accuracy the most.Based on a study of the pseudorange observation accuracy of different receivers and corresponding phase variance,a reasonable stochastic model was established.The GPS data from 56 IGS stations were connected to estimate the satellite clock and to analyze the positioning performance.The estimation results of the satellite clock based on this method prove to the positioning accuracy improve about 5%in comparison with the traditional clock estimation method.The stochastic model was employed to the positioning solution using the IGS satellite clock.Within 10 stations,the convergence time and positioning accuracy of 7 stations improved significantly.Compared with the traditional fixed weight method,the convergence time improves about 78%the most,and the positioning accuracy improves about 86.55%the most.