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Lidar echo signal is non-linear and non-stationary, which is often accompanied by various noises. In order to filter out the noise and extract valid signal information, a suitable method should be chosen for noise reduction. Some denoising methods are commonly used, such as the wavelet transform (WT), the empirical mode decomposition (EMD), the variational mode decomposition (VMD), and their improved algorithms. In this paper, a new denoising method named the WT-VMD joint algorithm based on the sparrow search algorithm (SSA), for lidar signal is selected by comparative experiment analysis. It is shown that this method is the most suitable one with the maximum signal-to-noise ratio (SNR), the minimum root-mean-square error (RMSE), and a relatively small indicator of smoothness when it is used in three kinds (50, 100, and 1000 pulses) of simulate lidar signals. The SNR is increased by 138.5%, 77.8% and 42.8% and the RMSE is decreased by 81.8%, 72.0% and 68.8% when being used to the three kinds of cumulative signal without pollution. Then, the SNR is increased by 83.3%, 60.4% and 24.0% and the RMSE is decreased by 70.8%, 66.0% and 50.5% when being used to the three kinds of cumulative signal with aerosol and clouds. The WT-VMD joint algorithm based on SSA is used in the denoising process for the actual lidar signal, showing extraordinary denoising effect and will improve the inversion accuracy of the lidar signal.<\/jats:p>","DOI":"10.3390\/s22165978","type":"journal-article","created":{"date-parts":[[2022,8,10]],"date-time":"2022-08-10T09:47:06Z","timestamp":1660124826000},"page":"5978","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":30,"title":["New Denoising Method for Lidar Signal by the WT-VMD Joint Algorithm"],"prefix":"10.3390","volume":"22","author":[{"ORCID":"https:\/\/orcid.org\/0000-0002-3648-6124","authenticated-orcid":false,"given":"Zhenzhu","family":"Wang","sequence":"first","affiliation":[{"name":"Key Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China"},{"name":"Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China"},{"name":"Advanced Laser Technology Laboratory of Anhui Province, Hefei 230037, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Hongbo","family":"Ding","sequence":"additional","affiliation":[{"name":"Key Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China"},{"name":"Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Bangxin","family":"Wang","sequence":"additional","affiliation":[{"name":"Key Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China"},{"name":"Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China"},{"name":"Advanced Laser Technology Laboratory of Anhui Province, Hefei 230037, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Dong","family":"Liu","sequence":"additional","affiliation":[{"name":"Key Laboratory of Atmospheric Optics, Anhui Institute of Optics and Fine Mechanics, Hefei Institutes of Physical Science, Chinese Academy of Sciences, Hefei 230031, China"},{"name":"Science Island Branch of Graduate School, University of Science and Technology of China, Hefei 230026, China"},{"name":"Advanced Laser Technology Laboratory of Anhui Province, Hefei 230037, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2022,8,10]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"59","DOI":"10.1007\/s11082-011-9503-6","article-title":"Noise reduction for lidar returns using local threshold wavelet analysis","volume":"43","author":"Mao","year":"2012","journal-title":"Opt. Quantum Electron."},{"key":"ref_2","first-page":"96","article-title":"LIDAR exploration of atmospheric boundary layer over downtown of Beijing in summer","volume":"29","author":"Wang","year":"2008","journal-title":"J. Appl. Opt."},{"key":"ref_3","first-page":"140","article-title":"Optical properties of aerosol derived from lidar measurements","volume":"15","author":"Zhou","year":"1998","journal-title":"Chin. J. Quantum Electron."},{"key":"ref_4","first-page":"144","article-title":"De-noising method for mie scattering lidar echo signal based on wavelet theory","volume":"45","author":"Zhou","year":"2016","journal-title":"Acta Photonica Sin."},{"key":"ref_5","doi-asserted-by":"crossref","first-page":"617","DOI":"10.1109\/18.119727","article-title":"Singularity detection and processing with wavelets","volume":"38","author":"Mallat","year":"1992","journal-title":"IEEE Trans. Inf. 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Commun."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1068","DOI":"10.3788\/CJL20093605.1068","article-title":"Empirical mode decomposition algorithm research & application of mie lidar atmospheric backscattering signal","volume":"36","author":"Zheng","year":"2009","journal-title":"Chin. J. Lasers"},{"key":"ref_10","first-page":"1443","article-title":"De-noising method research for lidar echo signal based on variational mode decomposition","volume":"48","author":"Xu","year":"2018","journal-title":"Laser Infrared"},{"key":"ref_11","first-page":"98","article-title":"Study on Signal Denoising of Microseismic Monitoring Based on Combined Variational Mode Decomposition and Wavelet Threshold Method","volume":"40","author":"Liu","year":"2020","journal-title":"Min. Res. Dev."},{"key":"ref_12","doi-asserted-by":"crossref","unstructured":"Zhang, Y.D., Hou, M., Liu, Z.L., and Xie, P. (2010, January 29\u201331). Empirical mode decomposition with wavelet de-noising. Proceedings of the 2010 IEEE International Conference on Intelligent Computing and Intelligent Systems, Xiamen, China.","DOI":"10.1109\/ICICISYS.2010.5658649"},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Hu, H., Ao, Y., Yan, H., Bai, Y., and Shi, N. (2021). Signal Denoising Based on Wavelet Threshold Denoising and Optimized Variational Mode Decomposition. J. Sens., 2021.","DOI":"10.1155\/2021\/5599096"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"167997","DOI":"10.1109\/ACCESS.2019.2949063","article-title":"Optimal VMD-based signal denoising for laser radar via Hausdorff distance and wavelet transform","volume":"7","author":"Hua","year":"2019","journal-title":"IEEE Access"},{"key":"ref_15","doi-asserted-by":"crossref","unstructured":"Li, X., Wang, L.X., and Duan, Z.Q. (2020). Application of improved adaptive wavelet noise reduction in laser gyroscope signal processing. Laser Optoelectron. Prog., 57.","DOI":"10.3788\/LOP57.210401"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"613","DOI":"10.1109\/18.382009","article-title":"De-noising by soft-thresholding","volume":"41","author":"Donoho","year":"1995","journal-title":"IEEE Trans. Inf. Theory"},{"key":"ref_17","first-page":"63","article-title":"Research on lidar echo signal denoising based on wavelet threshold method","volume":"43","author":"Wang","year":"2019","journal-title":"Laser Technol."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"936","DOI":"10.1007\/s10043-016-0275-x","article-title":"Relevant modes selection method based on Spearman correlation coefficient for laser signal denoising using empirical mode decomposition","volume":"23","author":"Duan","year":"2016","journal-title":"Opt. Rev."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2317","DOI":"10.1098\/rspa.2003.1123","article-title":"A confidence limit for the empirical mode decomposition and Hilbert spectral analysis","volume":"459","author":"Huang","year":"2003","journal-title":"Proc. R. Soc. Lond. A"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Wu, Q., and Liu, Y. (2020). De-noising methodf or gyroscope signal based on improved ensemble empirical mode decomposition. Laser Optoelectron. Prog., 57.","DOI":"10.3788\/LOP57.150601"},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"95","DOI":"10.1016\/j.sigpro.2014.10.038","article-title":"EMD interval thresholding denoising based on similarity measure to select relevant modes","volume":"109","author":"Yang","year":"2015","journal-title":"Signal Process."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"772","DOI":"10.1016\/j.ymssp.2018.07.033","article-title":"A novel comprehensive evaluation method of the draft tube pressure pulsation of Francis turbine based on EEMD and information entropy","volume":"116","author":"Wang","year":"2019","journal-title":"Mech. Syst. Signal Process."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"1685","DOI":"10.1103\/PhysRevE.49.1685","article-title":"Mosaic organization of DNA nucleotides","volume":"49","author":"Peng","year":"1994","journal-title":"Phys. Rev. E"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"349","DOI":"10.1016\/j.sigpro.2016.02.011","article-title":"Variational mode decomposition denoising combined the detrended fluctuation analysis","volume":"125","author":"Liu","year":"2016","journal-title":"Signal Process."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"48","DOI":"10.1016\/j.dsp.2014.06.006","article-title":"Detrended fluctuation thresholding for empirical mode decomposition based denoising","volume":"32","author":"Mert","year":"2014","journal-title":"Digit. Signal Process."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"22","DOI":"10.1080\/21642583.2019.1708830","article-title":"A novel swarm intelligence optimization approach: Sparrow search algorithm","volume":"8","author":"Xue","year":"2020","journal-title":"Syst. Sci. Control Eng."},{"key":"ref_27","first-page":"62","article-title":"Study on Quantum Noise of Photodetector","volume":"5","author":"Tao","year":"2010","journal-title":"J. Atmos. Environ. Opt."},{"key":"ref_28","first-page":"8","article-title":"Noise analysis for optoelectronic detector","volume":"32","author":"Xie","year":"2008","journal-title":"Inf. Technol."},{"key":"ref_29","first-page":"128","article-title":"A comparative study on validity assessment of wavelet de-noising","volume":"32","author":"Tao","year":"2012","journal-title":"J. Geod. Geodyn."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"482","DOI":"10.1175\/1520-0450(1972)011<0482:DOAHDB>2.0.CO;2","article-title":"Determination of aerosol height distributions by lidar","volume":"11","author":"Fernald","year":"1972","journal-title":"J. Appl. Meteorol."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"652","DOI":"10.1364\/AO.23.000652","article-title":"Analysis of atmospheric lidar observations: Some comments","volume":"23","author":"Fernald","year":"1984","journal-title":"Appl. Opt."}],"container-title":["Sensors"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/16\/5978\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,11]],"date-time":"2025-10-11T00:06:51Z","timestamp":1760141211000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1424-8220\/22\/16\/5978"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2022,8,10]]},"references-count":31,"journal-issue":{"issue":"16","published-online":{"date-parts":[[2022,8]]}},"alternative-id":["s22165978"],"URL":"https:\/\/doi.org\/10.3390\/s22165978","relation":{},"ISSN":["1424-8220"],"issn-type":[{"value":"1424-8220","type":"electronic"}],"subject":[],"published":{"date-parts":[[2022,8,10]]}}}