GNSS卫星钟差估计与结果分析

探讨了GNSS卫星钟差估计的基本原理、处理方法及数据处理中的一些关键技术,利用全球56个IGS跟踪站的观测数据进行钟差估计,比较分析了钟差产品的精度与定位性能。以GPS系统解算结果为例,其钟差产品与IGS最终精密卫星钟差符合较好,精度优于0.04ns(约0.012m),多系统钟差解算结果互差优于亚纳秒级。基于钟差产品进行精密单点定位解算试验,试验结果表明,在定位收敛之后,静态PPP在东、北、天3个方向上精度为0.0582m、0.0466m、0.1188m;动态PPP在东、北、天3个方向上精度为0.0671m、0.0640m、0.3200m。定位结果与IGS最终精密钟差解算结果符合较好,表明两者之间差异较小,进一步验证了解算得到的卫星钟差产品的定位性能。

Estimation and Result Analysis of GNSS Satellite Clock Error

The basic principle, processing method and some key techniques in GNSS satellite clock error estimation were discussed. The observation data of 56 IGS tracking stations around the world were used to estimate the satellite clock error, the accuracy and positioning performance of the clock products were compared and analyzed. Taking the GPS system solution as an example, the clock product was in good agreement with the final precision satellite clock of IGS, and the accuracy was better than 0.04ns (about 0.012m), mutual differences of multi-system clock error results were better than sub-ns. Based on the satellite clock product, the precise point positioning solution test was carried out. The test results showed that after the positioning convergence, the accuracies of static PPP in the three directions of E, N and U were: 0.0582m, 0.0466m, and 0.1188m; the accuracies of kinematic PPP in the three directions of E, N and U were: 0.0671m, 0.0640m, and 0.3200m. The positioning results were in good agreement with the final precision clock error calculation results of IGS, indicating that the difference between them was small, which further verified the positioning performance of the calculated satellite clock products.