弹性波全波形反演(EFWI)是目前理论上精度最高的弹性参数反演方法，可以为探索地球内部属性和油气勘探提供纵横波速度和密度。不同参数对地震波的耦合效应会在EFWI中产生交叉假象。用于消除这些交叉假象的反演策略依赖于数据质量和先验信息。Hessian矩阵能估计耦合效应并用于消除相应的交叉假象，但是巨量的计算需求阻碍其在大规模反演问题上的应用。而常规的对角近似Hessian矩阵无法消除参数耦合效应引起的影响。为了校正参数耦合效应引起的交叉假象，本课题基于申请人已经发表的块对角近似Hessian矩阵，拟发展一套基于带状近似Hessian矩阵的二维EFWI方法。需要使用代表强烈参数耦合效应的元素来构建带状近似矩阵，并将其整合到拟牛顿局部最优化方法中。该方法能克服引入Hessian有效信息时的计算和存储问题，同时又能显著地削弱多参数间的交叉脚印，可为大规模反演问题提供高精度的弹性参数模型。

Elastic Full Wave-form Inversion (EFWI) is the most accurate elastic parameter inversion method at present, which can provide P-, S-wave velocities and density for inner Earth investigation and oil-gas exploration. Coupled effects between different parameters produce cross-talk artifacts in EFWI. Inversion strategies used for removing these cross-talks depend on data quality and prior information. The Hessian matrix describes the coupled effects and can be used to correct the corresponding cross-talk artifacts. However, the Hessian matrix is normally avoided in large inversion problems due to excessive computational cost. Conventional diagonal-approximate Hessian matrix ignores the coupled effects and cannot mitigate the cross-talks in EFWI. In order to correct the cross-talk artifacts from the coupled effects, we propose to develop a new EFWI method using banded pseudo-Hessian matrix in this proposal, based on block-diagonal pseudo-Hessian matrix we developed. We first construct the banded pseudo-Hessian matrix with those elements describing significant coupled effects. Then we incorporate the banded pseudo-Hessian matrix into quasi-Newton optimization method. This new EFWI can overcome the drawback in computational cost and memory requirement of the Hessian computation. Meanwhile, it effectively corrects cross-talk artifacts from the coupled effects and provide high-accuracy elastic parameter models for large-scale inversion problems.