径向道变换压制相干噪声方法研究

Study on coherent noise attenuation using radial trace transform filtering

径向道变换(Radial Trace Transform)是将地震道集振幅值从偏移距-双程旅行时坐标系变换到视速度-双程旅行时坐标系,通过这种坐标系的变换,使相干噪声与有效信号在视速度和频率方面都有效分离.本文在介绍RT变换基本原理基础上,分析了RT变换中两种常用插值方法及其特点.并利用对模拟地震资料的处理,证明了RT域模拟-相减法较其带通滤波法在相干噪声压制与反射信号保持方面具有明显优势.最后,根据噪声特点,通过选择合理RT滤波参数,对实际地震资料进行处理试验,获得了较好的去噪效果,明显提高了资料信噪比,验证了研究方法的有效性.

The radial trace （RT） transform maps wavefield amplitudes from coordinates of offset and traveltime to those of apparent velocity and traveltime, and isolates coherent noise events in terms of both apparent velocity and frequency from the reflection wavefield. The paper describes the principle of radial trace transform, and compares the characters of two interpolation methods in common use. The model seismic data processing shows that the model-- subtract method is more superior to the bandpass filtering in coherent noise attenuation and effective signal reservation in the radial trace domain. Finally, according to the characters of noise, preferable processing result of a practical shot gather that has obviously improved S/N ratio is obtained after RT filtering with suitable filtering parameters. And the effectiveness of this method is demonstrated.