摘要
用多项式拟合、谱分析、改进的AR模型三种方法对由卫星双向时间频率传递得出的钟差时间序列进行了拟合和预报分析。为了抵制钟差时间序列中异常值的影响,引入了“抗差等价权”,利用卫星双向时间频率传递得到的1 d的钟差,按不同采样率、不同时间跨度进行计算分析。结果表明,抗差估计的预报精度明显高于最小二乘估计;平滑值的预报精度高于采样值;由于钟差时间序列中有明显的周期变化,多项式进行钟差预报的精度不可靠;用谱分析进行钟差预报的精度不高,但可以发现钟差时间序列中的主要周期变化;改进的AR模型预报精度最高,预报6 h钟差的RMS在1 ns左右。
Three functional models, polynomial, spectral analysis, and modified AR model, are fitted and compared in fitting and predicting the clock differences based on the data series derived from two-way satellite time and frequency transfer. A robust equivalent weight is applied, which controls the significant of outlying observations. Some conclusions show that the prediction precision of robust estimation is better than that of LS. The prediction precision calculated from smoothed observations is higher than that calculated from sampling observations. As a count of the obvious period variations in the time series, the prediction result of polynomial model is uncertainty. The prediction precision of spectral analysis is very low, but the main period variations can be determined. The 6-hour prediction RMS is 1 ns or so, when modified AR model is used.
出处
《武汉大学学报（信息科学版）》
EI
CSCD
北大核心
2007年第1期43-46,共4页
Geomatics and Information Science of Wuhan University
基金
总参测绘局预研课题基金资助项目
关键词
时间预报
时间比对
卫星双向时间频率传递
time prediction
time transfer
two-way satellite time and frequency transfer
