Abstract: Aiming at the multi-path errors and random noise of GNSS RTK technology in the deformation and displacement monitoring of offshore platform, a combined denoising algorithm based on cross-validation improvement of complete integrated empirical mode decomposition (CVCEEMDAN), wavelet threshold (WT) noise reduction method and singular spectrum analysis (SSA). Firstly, the original signal is decomposed by CEEMDAN, and the IMF components of noise and effective signal are identified by cross-validation method. Then WT and SSA are used to denoise the noise and effective signal components respectively, and the processed signal is reconstructed to obtain the real deformation monitoring results. The results show that this algorithm is adaptive and has better denoising effect than EMD, EEMD, CEEMDAN and ACCEEMDAN-WT-SSA algorithms. It can effectively remove multi-path errors and random noise in the deformation monitoring of offshore platform, and successfully obtain the real monitoring signal results.

Key words: GNSS RTK, offshore platform, cross-validation, singular spectrum analysis, wavelet threshold denoising