将全球IGS测站按照5°×5°范围进行格网化,从中均匀选取257个测站。对这些测站实测坐标序列进行非线性变化周期分析发现,周年频谱是绝大部分IGS站共有的非线性运动规律。通过对周年频谱进行相位拟合建模发现,南北半球绝大部分测站存在约180°的相位系统差。
We take the global IGS stations into 5°×5°grids.257 stations are chosen equably as subjects for the experiment.Through analysis of coordinate time series,we determine the annual motion in most of these IGS stations.Furthermore,we find that,after phase modelling,there is a systemic error of 180°between the southern and northern hemispheres in most of the stations.