Robust Spectral Analysis on Time Series of Geocenter Motion
Hairong Guo · 2003
In this paper, a robust spectral analysis method is put forward. The method is a combination of robust estimation and spectral analysis. The time series of geocenter motion from the 5-year GPS data of about 120 IGS stations is computed and analyzed based on the robust spectral analysis. The results show that the geocenter motion has different principal periods in different directions. Various geophysical phenomena have great intersecting effects on X direction, thus the principal periods cannot be separated. Principal periods are, however, obvious in Y and Z directions. There are annual, semi-annual, seasonal and monthly periods in Y direction. Annual periods makes a great contribution towards Y direction. For Z direction, the principal periods are annual, semi-annual, 51-day and 609-day periods. The amplitudes in Z direction are obviously larger than those in Y and Z directions.