High Accuracy Differential Prediction of UT1-UTC

Abstract

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.

Key words： Earth orientation parameters; UT1-UTC prediction; dual differential; AR model; earth zonal harmonic tidal correction