Denoising Method of the Φ-OTDR System Based on EMD-PCC

To filter out the phase noise of the Φ-OTDR system, a method based on empirical mode decomposition and Pearson correlation coefficient fusion (EMD-PCC) is proposed. First, the EMD-PCC method is simulated. The experimental results show that the SNR increases from 7.32 dB to 13.68 dB. Second, the beat signal detected by the Φ-OTDR system is demodulated by the I/Q quadrature demodulation method. Finally, the phase signal is decomposed by empirical mode decomposition to obtain the modal function and residual component. The Pearson correlation coefficient with the phase signal is calculated. Then, the threshold value is 0.4-1.0. The modal function within the threshold is superimposed with the residual component signal. In this paper, the experimental verification of PZT analog disturbance signal frequencies of 200 Hz, 300 Hz, 400 Hz and 500 Hz is performed. Then, wavelet denoising and EMD-soft denoising are compared with EMD-PCC denoising. Experimental results show that the proposed method can accurately restore the disturbance signal. The experiment of sawtooth disturbance signal frequencies of 400 Hz and 500 Hz verifies the applicability of the algorithm and shows that the method is suitable for other arbitrary forms of disturbance signals. The Φ-OTDR system has an important application in the field of oil and gas exploration. This method provides a good theoretical basis for the exploration field.