A combined denoising method of empirical mode decomposition and singular spectrum analysis applied to Jason altimeter waveforms: A case of the Caspian Sea  

作　　者：Wenguan Jiang Wei You 

机构地区：[1]Faculty of Geosciences and Environmental Engineering,Southwest Jiaotong University,Chengdu 611756,China [2]Third Geodetic Team of the Department of Natural Resources,Chengdu 610100,China [3]State-Province Joint Engineering Laboratory of Spatial Information Technology for High-Speed Railway Safety,Chengdu 610031,China

出　　处：《Geodesy and Geodynamics》2022年第4期327-342,共16页大地测量与地球动力学（英文版）

基　　金：We acknowledge the National Natural Science Foundation of China(grant number 41974013)for financial support.

摘　　要：During the satellite pulse propagation and reception, the altimeter waveform is inevitably affected by noise. To reduce the noise level in Jason altimeter waveforms, we used singular spectrum analysis(SSA),empirical mode decomposition(EMD), and the combination of SSA and EMD to obtain the denoised waveforms. The advantages of the combined method were verified and the accuracy of the mean sea surface height(MSSH) model was improved. Comparing the denoising effect of the three methods, the results show that the signal-to-noise ratio(SNR), correlation coefficient and root-mean-square error are effectively improved by the combination of SSA and EMD. The sea surface heights(SSHs) were remeasured with a 50% threshold retracker of denoised waveforms, and the MSSH model of the Caspian Sea with a grid of 1’× 1’was established from the retracked SSHs of Jason-1/2/3. Taking the mean value of the four models as a control, it is found that the model calculated by the combined denoising method has the highest accuracy. This indicates that using the combined denoising method to reduce the noise level is beneficial to improve the accuracy of the MSSH model.

关 键 词：Altimetry waveforms Jason-1/2/3 Combined method Waveform retracking Mean sea surface height 

分 类 号：P228.3[天文地球—大地测量学与测量工程]