一种全球导航卫生系统钟差估计优化方案的量化研究

摘要：针对卫星钟差解算策略的优化问题，本文基于BERNESE GNSS数据处理软件，设计了卫星估计钟差解算方案。提出了“单位时间误差梯度”的概念，量化了解算精密钟差的效率。采用基于TIN的选站法选取参考站，利用历元参数在历元间的独立性，分步解算各类参数。既减少了因大量历元参数存在引起的时间迟滞，又消除了单历元观测离群值对非历元参数估计的影响，从而提高了GNSS卫星钟差估计效率。利用IGS跟踪站作为参考站对以上解算过程进行实验，结果表明估计钟差与IGS精密钟差的符合精度达到0.1ns，陆态网精密单点定位（PPP）动态解最大偏差小于10cm，能够满足动态定位厘米级的精度要求，为估计钟差时参考站的数量和几何分布的选择提供了参考。

A Quantitative Study of GNSS Clock Estimation Optimization Scheme

Abstract: In order to optimize the solution algorithm of satellite clock, this paper designs a solution for estimating satellite clock based on BERNESE GNSS data processing software. The concept of "Gradient of unit time error" is proposed to quantify the efficiency of estimating precision clock. The reference station is selected based on the TIN-based station selection method, and the independence of the epoch parameters are used to solve various parameters step by step. It not only reduces the time delay caused by the existence of a large number of epoch parameters, but also eliminates the influence of single epoch observation outliers on the estimation of non-epoch parameters, thereby improving the efficiency of GNSS satellite clock estimation. Experimenting with the above solution process using the IGS tracking station as a reference station, the results show that the difference of the estimating clock and the IGS precision clock reaches 0.1 ns, and the maximum deviation of the precise point positioning(PPP) dynamic solution of the Crustal Movement Observation Network of China is less than 10 cm, which can meet the accuracy requirements of centimeter dynamic positioning, and can provide a reference for the selection of the number of reference stations and the choice of geometric distribution for estimating the clock .