iGMAS分析中心产品一致性分析及其应用研究

通过比较不同分析中心提供的精密轨道与钟差产品发现，不同分析中心的轨道和钟差表现出明显差异，并且轨道径向和钟差的相对偏差存在很强的相关性和周期特性。经过数据分析，BDS、GPS、GLONASS的轨道径向和钟差相对偏差具有12h和24h周期项，而Galileo具有12h周期项。因此，提出了一种新的钟差拟合及加权综合方法，通过建立多项式+不同周期项模型对钟差进行拟合求得残差序列，利用残差序列对不同分析中心产品的钟差值进行定权，并将加权均值作为钟差综合值。通过与ISC钟差对比发现，提出的钟差综合模型可以明显提高部分分析中心产品的钟差精度，并优化iGMAS分析中心钟差产品的一致性。

Research on Consistency Analysis and Application for Products from iGMAS Analysis Center

By comparing the precision orbit and clock offsets products provided by different analysis centers, it is found that the orbits and clock offsets of different analysis centers are obviously different, and the relative deviation of orbit radial and clock offsets has strong correlation and periodic characteristics. Through the data analysis, the relative deviation of orbit radial and clock difference of BDS, GPS and GLONASS has 12h and 24h cycle terms, while Galileo has 12h cycle terms. To solve the above problem, this paper proposes a new method to fit the clock offsets by establishing a polynomial + different periodic term model. The residual sequence which is used to weight the clock offsets of different analysis centers is resolved. So the weighted mean value of the two analysis centers is taken as the combination value of clock offsets. By comparing with ISC clock, the proposed combination clock model can significantly improve the accuracy of clock offsets products, and optimize the consistency of different analysis centers'' clock offsets products.