First, the trend,annual and semi-annual terms are removed by the least-square fitter from theSPACE98 time series which describes the polar motion of the Earth, the maincomponent in the resulted new series is the Chandler Wobble.

• 首先利用SPACE98数据，去掉其趋势项、周年项后，得到主要含Chandler项的激发序列；