高精度UT1-UTC差分预报方法研究

针对卫星导航所需的高精度地球定向参数(EOP)中的UT1-UTC预报问题,提出了基于双差分LS+AR的UT1-UTC参数预报方法。对UT1-UTC观测数据进行跳秒检测、固体地球带谐潮汐项改正,然后对改正后的UT1-UTC数据进行双差分处理,增强数据平稳性;采用最小二乘拟合(LS)与自回归(AR)分析方法对差分处理后的数据进行分析与预报;对预报结果进行逆差分处理与潮汐项改正外推、跳秒恢复,获取高精度的UT1-UTC预报值。通过与国际EOP_PCC预报结果对比表明,UT1-UTC短期预报精度与EOP_PCC较优的预报精度相当,其中1天UT1-UTC预报精度优于0.03ms,优于EOP_PCC预报结果。介绍了北京航天飞行控制中心的UT1-UTC每日例行预报情况。

High Accuracy Differential Prediction of UT1-UTC

This paper proposes a prediction method of UT1-UTC in Earth orientation parameters (EOP) by dual differential least-squares (LS) and autoregressive (AR) model. Firstly, leap seconds are removed in UT1-UTC observations, and Earth zonal harmonic tidal are corrected. Then, the corrected UT1-UTC are processed by dual differential method, the stationarity of polar motion parameters is improved. Then, LS+AR method is utilized to analyze the dual differential UT1-UTC to obtain the preliminary prediction results. Finally, the preliminary prediction results are processed by inverse dual differential method, and tidal correction are extrapolated and leap seconds are recovered to obtain high accuracy UT1-UTC prediction results. The prediction results are compared with EOP prediction comparison campaign (EOP_PCC) results. It shows that the short-term UT1-UTC parameters prediction error is at the same level of EOP_PCC. The one day prediction accuracy of UT1-UTC is less than 0.03ms, which is better than EOP_PCC one day UT1-UTC prediction accuracy. And, the daily routine UT1-UTC prediction in Beijing Aerospace Control Center is introduced.