地震干涉测量法近地表散射波分离技术

针对山地地震勘探数据低信噪比问题，近地表散射波分离意义显得尤为突出，地震干涉测量法为此提供了一种技术手段.本文将地震干涉测量理论和散射理论结合起来，导出了近地表散射波地震干涉测量表达式，分为互相关型和褶积型表达式，它们由实际波场和背景波场干涉测量构成.根据近地表散射波分离理论，结合陆上地震勘探实际观测系统，采用褶积和反褶积混合型地震干涉测量配置，用实际地震资料展示了近地表散射波分离技术的应用效果.经过理论分析和砾石区实际资料试验，表明地震干涉测量不仅能分离测线上散射源产生的散射波，而且能分离部分侧面散射波.该技术的优点在于它适应于起伏地形和不均匀近地表结构，并且不需要起伏地形和近地表速度信息.为了从实际资料中消除近地表散射波，本文采用多道匹配滤波自适应减法，在砾石区见到较好效果.

Separating the near-surface seismic scattered wave using seismic interferometry method

It is important to separate the near-surface seismic scattered waves from low signal-noise data in mountain seismic exploration, and seismic interferometry is one of promising methods. The seismic interferometry representations of the near-surface scattered wave are derived according to the seismic interferometry theory and the scattering theory. Those representations are composed of interferometry between actual wavefield and background wavefield and include cross-correlation type and convolution type seismic interferometry expression. According to the near-surface scattered wave separation theory and the geometry of land seismic exploration, the mixed configuration of convolution type and deconvolution type seismic interferometry is used. The application effect of the near-surface scattered wave method is showed using the real land seismic data. The theoretical analysis and real data tests in gravel area indicate that the seismic interferometry method can separate not only scattered wave generated by scattering sources on survey lines, but also partial side scattered wave. The advantages of this technology are that it adapts to the uneven terrain and the complex near-surface structure without information about topography and near-surface velocity. In this article, the subtraction method of multi-traces self-adaptive matched filter is used to eliminate the near-surface scattered wave from the real seismic data, and gets preferable results in gravel area.