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A Novel Method for Feature Extraction and Recognition of Echo Signal of Underground Cable

A new method for feature extraction and recognition of echo signal of underground cable is proposed. By this method, we use preprocessing to remove the direct coupled wave, set the threshold to segment the image, search the maximum energy of each horizontal position to extract hyperbolic characteristic points, and then use the least squares method for hyperbolic fitting. Based on this method, we can quickly recognize hyperbolic characteristics, extract the information of hyperbolic vertex, calculate the propagation velocity of electromagnetic wave in underground medium by weighted velocity method, and finally acquire the buried depth of underground cable. Based on finite difference time-domain method, the numerical simulation of the cable model under the soil is carried out. The method is applied to the forward analysis to verify the accuracy of the method, which provides the necessary information for the image modeling of the underground cable.