矿区/城市地震资料环境噪声的消除

针对矿区/城市三维地震资料中存在的外源噪声、单频噪声和成片强能量噪声等环境噪声,提出了利用小波变换技术,将含有上述环境噪声的单炮记录变换到时频域,通过不同的小波尺度突出不同的环境噪声;然后在具有环境噪声的小波尺度上应用拟合减去法消除外源噪声和单频噪声,采用逆向小波阈值去噪技术拟合并压制强能量噪声;最后通过小波重构得到消除环境噪声后的记录。利用理论模型和某矿区三维实际资料对上述方法进行了测试和分析,结果表明,该方法能够有效地消除各类环境噪声,并且对有效信号损害很小。

Attenuation of environmental noise in orefield/urban seismic data

Various ambient noises exist in orefield/urban 3D seismic data,such as external noise (hyperbolic noise),single-frequency noise and sliced strong energy.In order to attenuate the environmental noise,we utilized wavelet transform technique to transform the single shot record involving above ambient noise to time-frequency domain,and different ambient noise were highlighted by different wavelet scales.Then,at the wavelet scale with ambient noise,fitting subtraction method was used to remove external noise and single-frequency noise,and reverse wavelet threshold denoising technique was adopted to fit and suppress strong-energy noise.Finally,the seismic record without ambient noise was obtained by wavelet reconstruction.The method was tested on theoretical model and applied on 3D seismic data from some orefield.The result indicated that the method can effectively remove various ambient noise and has tiny damage on effective signals.