瑞利BOTDA系统的2维提升小波降噪方法

为了解决基于瑞利散射的布里渊光时域分析系统（BOTDA）中传感信号受噪声干扰严重的问题，采用2维提升小波变换算法，将测量信号从1维空间转换到2维空间，进行阈值降噪处理。通过理论分析和实验验证，取得了传统小波与2维提升小波降噪数据。结果表明，2维提升小波变换比传统小波变换信噪比提高约10dB，运算量减少了1/3；2维提升小波充分利用测量信号时间上的相关性，变换结构简单、运算速度快、降噪效果优于传统小波，适用于瑞利BOTDA系统降噪。该结果对光纤传感系统中信号降噪的研究有一定参考价值。

2-D lifting wavelet de-noising method for Rayleigh BOTDA system

In order to solve the problem that the sensor signal is seriously disturbed by noise in a Brillouin optical time domain analysis (BOTDA) system based on Rayleigh scattering, the 2-D lifting wavelet transform algorithm was used to convert the measured signal from 1-D space to 2-D space, and the noise was reduced by threshold. Through the theoretical analysis and experimental verification, the traditional wavelet and 2-D lifting wavelet denoised data were obtained. The results show that the signal-to-noise ratio of the 2-D lifting wavelet transform is about 10dB higher than that of the traditional wavelet transform, and the computation amount is reduced by 1/3. The 2-D lifting wavelet makes full use of the time correlation of the measured signal, the transformation structure is simple, the operation speed is quick and the noise reduction effect is superior to the traditional wavelet. It is suitable for noise reduction in a Rayleigh BOTDA system. The results of this paper are of great reference to the research of signal denoising in optical fiber sensing systems.