论文部分内容阅读
传统的地震逆散射广义Radon变换(GRT)保幅反演方法是建立在散射场一阶Born近似(单散射)的基础上,仅仅适用于弱扰动介质模型.本文从散射场积分方程出发,通过研究二次散射的特征,讨论和验证了基于局部二阶Born近似的GRT非线性保幅反演方法,将传统GRT线性保幅反演算子的适用范围扩展至非均匀强扰动介质.数值测试结果表明:在散射场近似模拟方面,二阶Born近似比一阶Born近似更为准确,二次散射效应主要集中在主散射点周围的局部区域内,超过这一范围,二次散射强度趋于稳定;在保幅反演方面,本文基于局部二阶Born近似的GRT非线性反演算法,明显优于传统的GRT线性反演算法,可以准确重构强扰动介质模型,而计算效率与线性反演方法相当.
Conventional seismic inverse scattering generalized Radon transform (GRT) amplitude preserving inversion method is based on the first-order Born approximation (single scattering) of scattering field, which is only applicable to weak perturbation medium model.Based on the scattering field integral equation, The characteristics of secondary scattering are studied, and the GRT nonlinear amplitude preserving inversion method based on local second-order Born approximation is discussed and validated, extending the applicability of traditional GRT linear amplitude preserving inversion operator to non-uniform strong perturbation medium. The results show that the second-order Born approximation is more accurate than the first-order Born approximation in the approximate simulation of scattering field. The second-order scattering effect mainly concentrates in the local area around the main scattering point, and the second-order scattering intensity tends to In the aspect of preserving amplitude inversion, the GRT nonlinear inversion algorithm based on local second-order Born approximation is obviously better than the traditional GRT linear inversion algorithm, which can accurately reconstruct the strong perturbation medium model and calculate the efficiency and linearity The method is pretty