Multi-channel Singular Spectrum Analysis of Geocenter Motion and Precise Prediction of Earth’s Motion

Abstract

AbstractGeocenter is the center of the mass of the Earth system including the solid Earth, ocean and atmosphere. The time-varying characteristics of geocenter motion (GCM) can reflect the redistribution of the Earth’s mass and the interaction between solid Earth and mass loading. The GCM also provides important support for millimeter level, dynamic real-time global reference framework. The GCM products determined from satellite laser ranging data released by the Center for Space Research through Jan. 1993 to Feb. 2017 is utilized to determine the periods and the long-term trend of GCM by using multi-channel singular spectrum analysis (MSSA). The results show that the GCM has the amplitude between 1 mm and 10 mm, and has obvious seasonal characteristics of the annual, semiannual, quasi-0.6 years and quasi-1.5 years in X, Y and Z directions, the annual characteristics make great domination. It also shows long period terms of 6.09 years as well as the trends of 0.05 mm/yr, 0.04 mm/yr and −0.10 mm/yr in the three directions, respectively. The MSSA is applied to predict GCM and combines it with the linear model (LM) and autoregressive moving average model (ARMA) to predict GCM with ahead 2 years. The results show that the LM+MSSA+ARMA model can effectively predict GCM parameters, and can provide prediction precision of 1.5 mm, 1.1 mm and 3.5 mm in X, Y and Z directions, respectively.KeywordsMulti-channel singular spectrum analysisGeocenter motionPredictionARMA