The Research On The Extraction Of Mine Based On The HHT

Extracting the characteristics effectively is the key of the underwater targets identification. Because of the lack of the underwater targets identification methods which based on the time-frequency analysis methods exist, in this paper, as a new method of time-frequency analysis, the Hilbert-Huang Transform Technology (HHT) is applied to the target characteristics extraction.The Hilbert-Huang transform (HHT) is a new theory, which is first developed by Huang et al at the end of last century for the signal analysis. This paper disserts the idea and how to achieve of HHT in detail, the local characteristics, the filter characteristics of the EMD method, the frequency resolution of marginal spectrum and the difference from Fourier spectrum. A new method to detect LFM is introduced because the reducing questions of suite filter from reverberation with Doppler, and then show the ability of detection. On the base of the emulation to highlight model of target echo, this paper disserts the ability of anti-reverberation. HHT is applied to the underwater target characteristics extraction, and this paper disserts the HHT method resolution ability of disparate amount geometry and elastic highlight. At last, this paper handles a mass of experiment data, prove the availability of identify actual mine. First of all, extracts the time-frequency characteristics of different targets echo by HHT. And then uses K-L transform to reduce the characteristics dimension. Classify the target which has the form of suspensor deposit and bury. Then discusses whether the experimental results fit with the theoretical discussion or not. The results show that this method can extract the highlight structure effectively, and achieving better results of classification and recognition by BP neural network classifier.With the result of simulation and actual data, HHT has the high hit ability to signal; the Hilbert marginal spectrum can open out the elastic part in the simple geometry with no Gibbs. The Hilbert spectrum can show the highlight structure effectively, and the time-frequency resolution is more accurately than CWT. HHT is an effectively method of underwater targets characteristics extracting.