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波在传播过程中与非均匀介质的相互作用是多年来地球物理研究的理论问题之一.用地震波探测地下地质结构时,介质的复杂性是相对于地震波长而言的.地震成像的效果与地下速度横向变化和地层的倾角密切相关.基于地震成像算子,研究地下非均匀介质复杂性的定量分析方法,实现定量表征地震成像过程中成像算子的角谱与地下介质地质非均质谱的相干作用.首先,将复杂地质构造表示为慢度非均质谱和倾角非均质谱,以此量化速度横向变化和地层倾角变化分布.其次,通过频散方程分析建立地震成像算子的角谱函数,以此描述其成像精度随慢度和传播角度的变化规律.最后,通过地下复杂构造的地质非均质谱与地震成像算子角谱的点积运算来定义该成像算子对给定地区复杂构造介质的成像效率η,其值越大,说明地震波的探测能力越强,复杂构造的地质复杂性就越小.因此,与地震成像效率相对应的非均匀介质变化的复杂系数可定义为?=1?η,从而实现对地下复杂介质地震探测复杂性的定量评估.
The interaction of waves with inhomogeneous media during propagation is one of the theoretical problems in geophysical research over the years. When seismic waves are used to probe underground geological structures, the complexity of the media is relative to the seismic wavelength. The effects of seismic imaging and Based on the seismic imaging operator, the quantitative analysis of the heterogeneity of underground heterogeneous media is studied to realize the quantitative characterization of the angular spectrum of the imaging operator and the geological heterogeneity spectrum of underground media Firstly, the complex geological structure is expressed as slow-rate heterogeneity spectrum and dip-angle heterogeneity spectrum to quantify the lateral variation of velocity and the change of dip angle of dip strata.Secondly, the angular spectral function of seismic imaging operator is established by dispersion equation analysis , So as to describe the variation rule of its imaging accuracy with the slowness and the propagation angle.Finally, through the dot product operation of the geological heterogeneity spectrum of the underground complex structure and the angular spectrum of the seismic imaging operator, the imaging operator is defined as complex The imaging efficiency η of the medium is constructed, the larger the value is, the stronger the detection ability of the seismic wave is and the less the geological complexity of the complex structure is Therefore, the complex coefficient of inhomogeneous media change corresponding to the seismic imaging efficiency can be defined as 1 = η, so as to realize the quantitative assessment of the complex seismic exploration complexity in the underground.