Abstract：In the process of empirical mode decomposition(EMD) denoising, there is inaccurate problem when using the correlation coefficient criterion to determine the inaccurate problem of the intrinsic mode function(IMF) K value. This paper adopts the composite evaluation index(T), considering the curve smoothness(r) and root mean square error(RMSE) of two indices, presenting an improved EMD denoising method. We verify the method using 9 simulated data and measured GPS elevation time series data from two reference stations of CMONOC. The experimental results show that the composite evaluation index is more accurate than single correlation coefficient index in determining K value, which can more reliably identify the boundary point between noise and signal, and the noise reduction effect is better.
