The present paper proposes a novel denoising method to suppress multi-source noise and enhance the signal-to-noise ratio (SNR) of the phase-sensitive optical-time-domain reflectometer (Ф-OTDR). The method is based on complete ensemble empirical mode decomposition with adaptive noise (CEEMDAN) and the interval thresholding. Firstly, the CEEMDAN is applied to the vibration signals to obtain a series of functions called the Intrinsic Mode Functions (IMFs). Secondly, the trip point is determined according to the fact that the product of energy density of the IMF and its corresponding averaged period is a constant. Then, the IMFs of noise dominant mode are treated with interval thresholding, and finally the IMFs and residual are reconstructed to obtain denoised signals. The results show that the SNR of disturbance location increases to 51.21 dB and 52.11 dB respectively, which represents a great improvement when compared with the other two methods.

中文翻译：

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Φ_OTDR系统中基于CEEMDAN和区间阈值的SNR增强方法

本文提出了一种新的去噪方法来抑制多源噪声并提高相敏光时域反射仪(Ф-OTDR)的信噪比(SNR)。该方法基于具有自适应噪声的完全集成经验模式分解 (CEEMDAN) 和区间阈值。首先，CEEMDAN 应用于振动信号以获得一系列称为本征模式函数（IMF）的函数。其次，根据IMF的能量密度与其对应的平均周期的乘积为常数来确定跳闸点。然后对噪声主导模式的IMF进行区间阈值处理，最后重构IMF和残差，得到去噪后的信号。结果表明，干扰位置的 SNR 增加到 51.21 dB 和 52。