把小波变换模极大值去噪法和小波变换阀值去噪法应用于noissin模拟噪声信号和某水电站岩石高边坡安全监测资料,根据信号和噪声在小波变换各尺度上的不同传播特性,剔除由噪声产生的模极大值点,保留信号所对应的模极大值点,利用剩余模极大值点重构小波系数,恢复原有监测信号。并通过信噪比、去噪信号能量比、去噪信号与原信号标准差三个性能指标,比较二者的去噪性能。实例应用表明,小波变换模极大值去噪法能够更有效地去除噪音突变信号,保留原始有用信号的突变点,重构信号能够更光滑地重现原始信号,比小波变换阀值去噪法性能更佳,具有更好的实际应用价值。
Wavelet transform is attempted to be applied to safety monitoring. The method eliminates modular maximum caused by the noise, reserves the modular maximum caused by the useful signal using wavelet transform based on the different propagation characteristics of the signal and noise on the different scales, reconstructs wavelet coefficient using maximum residual modular and recoveries the primary monitoring signal. The denoising method of wavelet transform modular maximum and wavelet threshold are applied to two actual cases, simulating noise signal noissin and safety monitoring data of the high rock slope of Jinping First Stage Hydropower Station. By the comparison of the three performance indexes, the signal-to-noise ratio, energy ratio of the denoising signal and standard deviation of the denoising signal to the original signal, the studies reveal that the former method is better and can effectively remove noise mutational signal and reserve useful mutational signal. It shows that the former method can be well applied to the safety monitoring data processing in geotechnical engineering.