瑞利BOTDA系统小波降噪新方法

基于瑞利散射的布里渊光时域分析系统(BOTDA)因为单端入射的特性而有广泛的应用前景.研究了应用提升小波变换对传感信号进行降噪,与传统小波变换相比,提升小波变换结构简单,运算速度快,易于硬件实现.分别利用累加平均法、传统小波变换和提升小波变换对瑞利BOTDA系统传感信号进行降噪,通过信噪比、均方误差和计算时间对三种方法的降噪效果进行比较.结果表明,累加平均法将信噪比提高了约14 dB,传统小波变换将信噪比提高了约18 dB,计算速度是累加平均法的3.26倍.提升小波变换将信噪比提高了约19 dB,计算时间仅为传统小波变换的约60％.结果表明,提升小波变换适用于瑞利BOTDA系统实时降噪处理.

New Wavelet De-noising Method for Rayleigh BOTDA System

The Brillouin optical time domain analysis (BOTDA) based on Rayleigh scattering has a wide application prospect because of the characteristics of single-ended incidence. The lifting wavelet transform is used for de-noising, compared with the traditional wavelet transform, it is simple, fast and easy to implement. The noise is reduced by applying the average method, the traditional wavelet transform and the lifting wavelet transform to the Rayleigh BOTDA system. The signal to noise ratio (SNR), mean square error (MSE) and calculation time are measured to make a comparison of the three methods. The results show that the average method improves the signal-to-noise ratio by 14 dB. The traditional wavelet transform increases the signal-to-noise ratio by 18 dB and the calculated speed is 3.26 times faster than the cumulative average method. The lifting wavelet transform increases the signal to noise ratio by 19 dB, and the computation time is 60% shorter than that of the traditional wavelet transform. It is proved that the lifting wavelet transform is suitable for real-time noise reduction of Rayleigh BOTDA system.