基于广义延拓逼近法的QZSS卫星钟差内插精度分析

卫星钟差数据插值是高精度定位数据处理中的重要环节，其插值结果直接影响定位精度，但常用的插值或拟合方法具有不同缺点. 本文尝试将广义延拓逼近法应用于准天顶卫星系统(QZSS)卫星钟差数据的处理中，介绍了Lagrange插值法、切比雪夫拟合法和广义延拓逼近法的原理，以及滑动式与非滑动式的区别；然后使用QZSS钟差数据探讨三种方法的参数(组)取值与插值结果精度的关系；最后比较三种方法在各自最优参数(组)取值情况下对QZSS卫星钟差的插值精度. 结果表明:选取合理的参数组合，广义延拓逼近法完全适用于QZSS卫星钟差的插值，且插值精度明显高于其他两种方法. 

Accuracy analysis of generalized extension interpolation method in QZSS satellite clock bias interpolation

The satellite clock error data interpolation is an important link in process of high accuracy positioning data, which has directly impact on positioning accuracy. However, the common interpolation and fitting methods have different disadvantages. The generalized extension approximation method is tried to apply to the process of Quasi-Zenith Satellite System (QZSS) satellite clock error data in this paper. The principles of Lagrange interpolation, Chebyshev fitting and Generalized extension approximation method are firstly introduced, and the differences between sliding and non-sliding. Afterwards, QZSS clock error data is used to discuss the relationship between the parameters (groups) value of the above three methods and the interpolation results accuracy. Finally, when the three methods take their respectively optimal parameters (groups), the accuracy of QZSS satellite clock error is compared. The simulation results show, as long as reasonable parameter combination is selected, that the generalized extension interpolation is completely suitable to QZSS satellite clock error, and the interpolation accuracy of the generalized extension approximation method is significantly higher than other two methods.