弹性波动方程叠前逆时偏移

从弹性波动方程出发，推导了二维各向同性介质情况下弹性波塑时传播的高阶差分格式，实现了弹性波在数值空间中的逆时延拓，从程函方程出发，采用逆风差分格式求取网格空间中各点的直达波旅行时，以此作为弹性波逆时偏移的成像条件（激发时间成橡条件），实现多波多分量资料的逆时偏移，文中给出了几个典型模型的理论记录的偏移结果，数值试验表明，逆时偏移能够使地表接收到的波场准确归位，提高资料处理精度。

Pre-Stack Reverse Time Migration of Elastic Wave Equation

Based on the elastic equation, a high|order difference scheme was established which can achieve reverse|time propagation of elastic waves in 2D isotropic media. An upwind finite|difference scheme of eikonal equation along expanding wave fronts was used to calculate the minimum travel time of each grid point called the excitation|time imaging condition in reverse|time migration. Using these two techniques, the authors have implemented the reverse|time migration of synthetic seismic data of some representative models. The result shows that the algorithm can image the subsurface medium properly, and improve the precision of data.