基于复合稀疏去噪的沙漠地震噪声消减

Desert Seismic Noise Attenuation via Compound Sparse Denoising

沙漠地震噪声既含有低频噪声又含有高斯白噪声,一般方法很难同时去除这两种噪声,针对此问题提出了使用复合稀疏去噪同时压制沙漠地震噪声中的低频噪声和高斯白噪声的方法。在复合稀疏去噪中将平方损失作为损失函数的保真度约束,将信号和信号一阶导数的L1范数作为损失函数的稀疏约束,然后通过最小化损失函数去除信号中的高斯白噪声。为同时去除低频噪声,复合稀疏去噪中联合使用了低通滤波器,即可一次性去除低频噪声和高斯白噪声。分别对模拟地震数据和实际地震数据进行仿真实验,实验表明该方法可有效地同时压制沙漠地震数据中的低频噪声和高斯白噪声,复合稀疏去噪的保幅略好于带通滤波器,去噪后带通滤波器会产生较严重失真,而复合稀疏去噪的失真较小。

Some denoising method can not attenuate the noise in desert seismic signal because it has both low frequency noise and Gauss white noise in desert seismic signal. CSD（ Compound Sparse Denoising） method is proposed to attenuate the low frequency noise and Gauss white noise in desert seismic signal simultaneously. In the compound sparse denoising,square loss is used as the fidelity constraint of the loss function,the L1 norm of the first derivative of signal and the signal itself are used as sparse constraint of the loss function. The Gauss white noise in the signal can be removed by minimizing the loss function. In order to remove the low frequency noise at the same time,compound sparse denoising combines the low pass filter so that the low frequency noise and the Gauss white noise can be removed. Tests on both synthetic records and real desert seismic signal indicate that compound sparse denoising can attenuate both low frequency noise and Gauss white noise in desert seismic signal. The composite sparse denoising is better than the bandpass filter in amplitude preserving,and the bandpass filter will produce more serious distortion after denoising,while the distortion of hte composite sparse denoising is smaller.