【摘要】 采用新近提出的改进型不规则最短路径多次波射线追踪正演技术,结合共轭梯度法求解带约束的阻尼最小二乘最优化反演问题,讨论了三维复杂层状模型中利用多震相走时资料进行联合反演成像的技术方法.考虑到不同震相种类走时的拾取误差不同,反演算法中引入了不同震相种类数据的权系数;另外,考虑到同时反演速度模型和反射界面起伏中不同参数变化对走时影响程度的不同,Jacobi偏导矩阵元素中引入了不同种类参数的归一化因子.几种数值模拟实例表明:多震相走时的联合或同时反演成像是一种提高走时成像空间分辨率,进而降低重建速度模型失真度行之有效的方法技术.更多还原

【Abstract】 By exploring a newly developed multiple(reflected,transmitted and converted)arrival tracking algorithm with modified irregular shortest-path method,and combining the conjugated gradient method to solve the constrained,damped least square problem,we discuss and analyze a simultaneous inversion algorithm combining different travel time datasets in 3D complex layered media.In the inversion process we introduce different weighting factors according to the different picking errors of different sets of arrival times.In order to balance the influence on the two different model parameters in simultaneous inversion,we normalize two different model parameters in Jacobi matrix in the inversion process.The numerical results show that it is a practical and efficient way to improve the spatial resolution and reduce the artifact in reconstructing velocity distribution and reflected subsurface interface.更多还原