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传统的走时层析反演都是依赖于射线理论,而实际地震资料的带限特征与射线理论无限高频的假设存在理论上的矛盾.针对传统的射线层析存在的上述问题,本文从频率域波动方程的Born和Rytov近似入手,推导出菲涅尔带走时层析敏感核函数,其与传统的射线层析方法的显著区别在于它建立在带限地震波与第一菲涅尔带的理论基础上.通过射线走时残差与Rytov近似走时残差的比较,本文提出了依据Rytov近似走时残差的菲涅尔层析反演方法.表层速度模型试算结果表明,相对于传统的射线走时层析,基于频率域波动方程的菲涅尔带走时层析成像方法具有更高的成像精度与分辨率.
The traditional time-lapse tomography inversion relies on the ray theory, but there are theoretical contradictions between the band-limited features of the actual seismic data and the infinite high-frequency ray theory.According to the above problems in the traditional ray tomography, The Born and Rytov approximations of the wave equation of the field are used to derive the Kernel Sensitivity Kernel Functions for Fresnel Zone Walk, which is significantly different from the traditional ray tomography method in that it is based on the Bounded Seismic Wave and the First Fresnel Zone Based on the comparison of Rayleigh walk residuals and Rytov approximate walktime residuals, a Fresnel tomographic inversion method based on Rytov approximate traveltime residuals is proposed in this paper.Experimental results of surface speed model show that compared with traditional ray Time-lapse tomography, Fresnel zone tomography method based on frequency-domain wave equation has higher imaging accuracy and resolution.