利用小波阀值降噪技术提高微地震信号的信噪比

To Improve Signal Noise Ratio of Micro-seismic Signal by Wavelet Threshold Denoising

微地震检测技术在工程施工、地质灾害防治等方面有着重要的作用,同时微地震信号又有信号能量弱,易受背景噪声干扰的特性,造成微震信号的初至无法准确拾取,导致微地震事件的定位不准确。该文利用小波阀值降噪技术对微地震检测信号进行降噪处理,并在Matlab平台对微震信号进行实验。通过对小波基特性的分析选出最优小波基,并使用时间序列的噪声检测方法来确定分解层数,再对分解信号通过阀值降噪去掉部分噪声干扰从而达到提高微地震信号信噪比的目的。

The micro-seismic detection technology plays an important role in the construction,geologic hazard prevention and control,while the signals of micro-seismic have the characteristics such as weak signal energy,easy to be disturbed by background noise,These lead to the beginning of micro-seismic signals can not pick up accurately,and lead to micro-seismic location events inaccurate. In this paper,the wavelet threshold denoising technology is used to reduce the denoise of micro-seismic monitoring signals,and based on Matlab platform,the micro-seismic signal is tested. Through analysing of the characteristics of wavelets,optimal wavelets is selected,and using the noise detecting in time-series to determine the number of decomposition piles. Then part of noise disturbing of decomposition signals is done away with the threshold denoising. Through this the signal noise ratio of micro-seismic increases.