陆上多次波识别与压制

陆上多次波与海上多次波均会干扰有效波信号，使地震资料信噪比降低，不同的是海上多次波覆盖了整条地震测线，而陆上地震数据中仅有部分共中心点道集（CMP）受到多次波干扰。 根据陆上多次波的特点，分析多次波在速度谱、常速扫描叠加剖面和动校正道集上所表现的地震特征，利用多次波识别方法，确定地震数据中多次波的分布范围，并在含有多次波的 CMP 动校正道集上，采用抛物线拉东变换方法压制多次波。 模型算例和实际地震数据应用结果表明，抛物线拉东变换方法不仅能压制陆上多次波，而且不伤害一次波反射信号，达到了保真去噪的目的。

Recognition and attenuation of multiples in land seismic data

Multiples in land seismic data and multiples in marine seismic survey could interfere with primary reflections and resulted in low signal to noise ratio of seismic data. However, multiples in land seismic data, unlike multiples in marine seismic data, only contaminate partial continuous common midpoint （CMP） gathers rather than the whole data sets. According to the property of multiples in the land seismic data, seismic reflection characteristics of multiples in velocity spectra, constant-velocity scan sections and normal movement correction gathers were analyzed. The CMP ranges were determined in the seismic data by multiple recognition methods, and the parabolic Radon transform was used to suppress multiples in the NMO gathers with multiples. The results of synthetic and field seismic data processing show that parabolic Radon transform method could suppress the multiples of land seismic data, and does not damage the primary reflections during multiple processing, achieving the effect of fidelity denoising.