三种速度场模型在CORS基准站时间序列中的对比分析

Comparative analysis of three velocity field models in CORS base station time series

速度场建模方法研究对全球卫星导航坐标时间序列分析具有重要意义。针对Ordinary Kriging法对分布稀疏点和区域边界点建模精度不高的问题,本文运用顾及高程因素影响的Ordinary Kriging单一改进模型和K-means-Ordinary Kriging组合模型对速度场进行建模。结果表明,两种改进模型都可以提高Ordinary Kriging基础模型的建模精度。其中,单一改进模型建模结果在SHK5点的改进最突出,高达8.66 mm/a;组合模型建模结果在NLIB点的最大改进达到8.22 mm/a。从测区全部CORS点的STD值来看,组合模型对点密度相对低和边界点的速度场建模效果更好。

The research on velocity field modeling method is of great significance to the time series analysis of global satellite navigation coordinates.Hence,the velocity field is modeled in this paper by using the improved Ordinary Kriging single model and the K-means-Ordinary Kriging combination model that take into account the influence of elevation factors to solve the problem that the Ordinary Kriging method cannot meet the accuracy requirements in modeling distribution sparse points and regional boundary points.The results show that both of the two improved models can improve the modeling accuracy of the basic Ordinary Kriging model,among which the modeling of the improved single model can get the most prominent improvement at SHK5 point,up to 8.66 mm/a,while the maximum improvement of 8.22 mm/a from the combined model modeling at NLIB point.The combined model can get a better modeling effect on the velocity field of the relatively low point density and boundary points from the perspective of STD value of all CORS points in the surveyed area.