Research On The Method Of Underwater Acoustic Transient Signal Detection Based On Hilbert Huang Transform

Underwater transient signal detection is always the emphasis and difficulty in the signalprocessing field. The one hand, the complex underwater acoustic environment and low SNRput signal detection into inconvenience. On the other hand, transient signals always contain awealth of target signature information, which have great significance to the signal detection,estimation and recognition. So it is the favour of domestic and foreign scholars for so long.Firstly, some typical transient signal detection methods were introduced briefly, and theproposition and the research survey of Hilbert-Huang Transform were analysed. From the tworespects of empirical mode decomposition and Hilbert spectrum, the theory of Hilbert-HuangTransform was introduced systematically, and the mode decomposition and Hilbert spectralanalysis of multi-component signals simulations was achieved. Then one type of pre-whitedprocessing method based on Empirical Mode Decomposition (EMD) was introduced, which isEnsemble Empirical Mode Decomposition (EEMD). The characteristics of EMD and EEMDwere mainly studied, including completeness, orthogonality, frequency resolution ratio,boundary etching, and so on. The deficiency of EMD was pointed out. It was showed bysimulation that the mode mixing haven’t been resolved radically by EEMD. The binary filtercharacteristics of mode decomposition were analysed emphatically.Then, based on the mathematic model of transient signal, three methods were proposedwhich were found on EEMD, Hilbert-Huang Transform reconstruction and the energy densitylevel. By drawing the receiver operating characteristic (ROC) curve, the detectionperformances of last two methods were compared with the traditional energy detection’s.Finally, the feasibility and validity of the methods in this paper were verified by processingthe lake and sea trial data.