Time series analysis of geocenter motion based on EMD method

doi:10.13474/j.cnki.11-2246.2019.0034

Abstract

Abstract:

The high-frequency information mixed with geocenter motion time series will affect the analysis of the geocenter motion. This paper uses the EMD method to decompose and reconstruct the geocenter motion time series from 2007 to 2017 calculated by translation approach using the GNSS solution provided by the IGS, then removes high-frequency terms, and performs the further analysis using the reconstructed geocenter motion time series. The results show that the geocenter motion calculated in the T_x, T_y, and T_z directions are at the millimeter level. The reconstructed time series using EMD method preserves the basic information of the original time series, weakens the influence of high-frequency terms, and improves the contribution rate of each periods, contribution rate in three directions increase by 12.3%, 16.7% and 6.3% respectively. By analyzing the reconstructed time series, the annual amplitudes in three directions are maximum, compared to other period, which are 2.32, 1.89, and 2.07 mm, respectively. In addition, the long-term trends in the T_y and T_z directions are more pronounced than those of T_x, which are 0.13 and -0.27 mm/a, respectively. The semi-annual term is weak and has a time variant features in the T_x and T_y directions. Moreover, some other minor interannual variations have also been discovered.

Key words: geocenter motion, translation approaches, empirical mode decomposition, time series analysis

CLC Number:

P228

QIAO Lingna, ZHAO Chunmei, MA Tianming. Time series analysis of geocenter motion based on EMD method[J]. 测绘通报, 2019, 0(2): 6-11.

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