灰色模型与二次多项式模型组合的GNSS时差预测

Prediction of GNSS time difference based on combination of Grey model and quadratic polynomial model

为实现多模组合导航,必须确定各导航系统之间的时间差。利用中国科学院国家授时中心(NTSC)双模双频时差监测型接收机输出的数据文件,通过分别计算本地时与GPS时、GLONASS时的偏差间接计算两系统间的时间偏差。采用灰色预报模型和二次多项式模型进行联合时差预报,对实测时间偏差值与预报时间偏差值之间的残差进行分析。试验结果表明与传统的二次多项式模型预报相比,组合预报结果的精度有所提高。

For realizing the multimode combined navigation, it is necessary to determine the time differences between the different navigation systems. In this paper, the data outputted from a dual-mode/dual-frequency time-difference monitoring receiver, which is operated in the time keeping laboratory of the National Time Service Center(NTSC), is used for calculating the time differences between the local time and GPST/and GLONASST, then the time difference between GPST and GLONASST can be calculated indirectly. The Grey model and the quadratic polynomial model are combined for predicting the time differences, and then the residuals between the measured time difference and the predicted time difference are analyzed. The results show that the accuracy of the combination prediction algorithm is better than that of the traditional quadratic polynomial algorithm.