ANALYSIS ON TIME SERIES OF TWO CORS STATIONS'HEIGHT BASED ON EMD
基于经验模式分解的CORS站高程时间序列分析

The time-frequency analysis method base on EMD(empirical mode decomposition) for GPS height time series is put forward.Taking two national CORS stations’ GPS height time series as an example,each intrinsic mode function is decomposed and the contribution rate of variance is also calculated.The problem of identifying father distinguishing the periodical signals and the trend is emphasizerd.The results indicate that it is only meaningful to distinguish the periodical and the trend signal on certain length of time series’ section.The trend based on EMD or EEMD presents with large curvature while the traditional form of periodical fitting function only linear form.