一种新的双树复小波在Φ-OTDR信号降噪中的应用

Application of a New Dual-tree Complex Wavelet inΦ-OTDR Signal Denoising

相位敏感光时域反射系统探测脉冲光在光纤中的后向瑞利散射信号也随着传感距离的增加而变得微弱,最后湮没在噪声中,限制了探测距离。介绍了小波变换、离散小波去噪和双树复小波去噪的基本原理。新的双树复小波去噪增强了信号分解的平移稳定性,改善了频率混叠现象,提出了基于邻域多尺度去噪和基于局部拟合良好度的阈值去噪策略,经仿真,该方法在Φ-OTDR信号降噪性能优异。

The phase-sensitive optical time-domain reflection system detects the backward Rayleigh scattering signal of pulsed light in the optical fiber as the sensing distance increases,and finally becomes annihilated in the noise,which limits the de⁃tection distance.The basic principles of wavelet transform,discrete wavelet denoising and dual-tree complex wavelet denoising are introduced.The new dual-tree complex wavelet denoising enhances the translation stability of signal decomposition and improves the frequency aliasing phenomenon.A threshold denoising strategy based on neighborhood multi-scale denoising and local goodness of fit is proposed.After simulation,the The method has excellent noise reduction performance inΦ-OTDR signal.