基于双树复小波域主成分分析的地震面波压制方法

Dual-tree Complex Wavelet Domain Principal Component Analysis for Seismic Ground Roll Attenuation

面波是地震勘探中一种主要的规则干扰波,面波压制是地震处理中的重要问题之一.结合双树复小波变换和主成分分析提出了一种面波压制方法.首先,对含面波地震信号进行双树复小波变换,在变换域中分析面波信号与有效信号的分布情况.鉴于低频子带既含较多有效信号又有较强的面波成分,对其进行主成分分析处理.对分解得到的每一尺度高频小波系数中±45°方向作主成分分析处理,±75°方向进行基于分位数的阈值处理,±15°方向保持不变.最后,对处理后的小波系数进行逆变换得到压制面波后的地震信号.仿真实验及对实际资料的处理结果显示,该方法能够有效压制面波,去除随机噪声,较好地保留了有效信号.

In order to improve the resolution of seismic data to facilitate the interpretation of seismic data,the ground roll attenuation becomes a research hotspot.A method is proposed for ground roll attenuation by combining the dual-tree complex wavelet transform with the principal component analysis(PCA).The distribution of the ground roll and the reflected wave in the dual-tree complex wavelet domain is analyzed.The low frequency coefficients are processed by the PCA because they contain the ground roll and reflected wave coefficients.For each scale,the high frequency coefficients for the±45°orientation are processed by the PCA.The high frequency coefficients for the±75°orientation are processed by the threshold based on the quantile.The high frequency coefficients for the±15°orientation are unchanged.The denoised seismic signal is gotten based on the dual-tree complex wavelet inverse transform.The proposed method can suppress surface wave effectively,remove random noise,and retain effective signal well.