二维小波变换与中值滤波联合去噪方法研究

由于随机噪声是一种频带较宽的干扰波,因此依靠单一的去噪处理方式往往难以获得清晰反映目标体的地震信息。小波变换能够较好的去除高斯噪声,保留有效波中、高频成分,提高记录的信噪比,但去除脉冲噪声的效果却并不理想;中值滤波具有良好的边缘保持特性,虽低频去噪声效果有限,但去除脉冲噪声效果明显。因此可利用二维小波变换与中值滤波优势互补的方法,进行叠前去噪处理,达到去除宽频随机噪声的目的。首先运用二维小波变换的理论,采用自适应门限阀值方法进行去噪,同时结合中值滤波方法联合去噪。模型与实际数据的应用效果表明,联合去噪方法可有效压制噪声能量、保留高频有效信号、提高地震记录信噪比与分辨率。

A Study on 2D Wavelet Transform and Median Filtering Jointed Denoising Method

Since the random noise is a kind of disturbing wave with broader wave band,thus rely on a single denoising mode is hardly to acquire seismic information can reflect target clearly.The wavelet transform can denoise Gaussian noise better,save intermediate and high frequency components in effective wave,improve record S/N ratio,but effect of impulse noise elimination is no good;while median filtering has good edge preserving characteristics,although low frequency denoising effect is limited,but impulse noise elimination effect in evidence.Thus can use the two methods＇ complementary advantages carry out prestack denoising,to eliminate wide frequency random noise.Using 2D wavelet transform theory,carry out self-adaption threshold denoising first,then in combination with median filtering jointed denoising.Applied effect of model and actual data has demonstrated that,jointed denoising can suppress noise energy effectively,preserve high frequency effective signal,and improve seismic record S/N ratio and resolution.