Separation of Geophysical Signals in the LAGEOS Geocenter Motion based on Singular Spectrum Analysis
Hongjuan Yu , Krzysztof Sośnica , Yunzhong Shen
AbstractWe recompute the 26-year weekly Geocenter Motion (GCM) time series from 1994 to 2020 through the network shift approach using Satellite Laser Ranging (SLR) observations to LAGEOS1/2. Then the Singular Spectrum Analysis (SSA) is applied for the first time to separate and investigate the geophysical signals from the GCM time series. The Principal Components (PCs) of the embedded covariance matrix of SSA from the GCM time series are determined based on the w-correlation criterion and two PCs with large w-correlation are regarded as one periodic signal pair. The results indicate that the annual signal in all three coordinate components and semi-annual signal in both X and Z components are detected. The annual signal from this study agrees well in both amplitude and phase with those derived by the Astronomical Institute of the University of Bern and the Center for Space Research, especially for the Y and Z components. Besides, the other periodic signals with the periods of (1043.6, 85, 28), (570, 280, 222.7), and (14.1, 15.3) days are also quantitatively explored for the first time from the GCM time series by using SSA, interpreting the corresponding geophysical and astrodynamical sources of aliasing effects of K1/O1, T2 and Mm tides, draconitic effects, and overlapping effects of the ground-track repeatability of LAGEOS1/2.
|Journal series||Geophysical Journal International, ISSN 0956-540X, e-ISSN 1365-246X, (N/A 100 pkt)|
|Publication size in sheets||0.75|
|Keywords in English||Reference systems; Satellite geodesy; Space geodetic surveys; Time-series analysis|
|Score||= 100.0, 18-03-2021, ArticleFromJournal|
|Publication indicators||: 2018 = 1.35; : 2019 = 2.574 (2) - 2019=2.834 (5)|
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