旋转交错网格VTI介质波场模拟与波场分解  

The simulation and decomposition of the wave-fields in VTI media by the rotated staggered grid

作　　者：王亚妮[1] 李长江[1] 李庆春[1] 

机构地区：[1]长安大学地质工程与测绘学院,西安710054

出　　处：《物探化探计算技术》2015年第2期198-202,共5页Computing Techniques For Geophysical and Geochemical Exploration

基　　金：国家自然科学基金(41374145;41304105);教育部博士点基金(20120205130002)

摘　　要：通过旋转交错网格高阶有限差分法对一阶速度应力弹性波动方程进行了波场模拟,将耦合的纵、横波场分别投影到纵波、横波的极化向量上纵、横波的分离,然后将分离之后的纵波、横波场按照矢量极化向量的比例再分配,达到了将纵、横波场分解,分解之后矢量波场的和与分离分解之前的矢量波场的和相等。由于分离分解是在旋转交错网格下进行的,因此不需要对波场进行近似或插值处理,提高了波场分解的精度。通过对均匀介质模型和复杂层状介质模型分解前、后波场快照与地震记录的对比,验证了该方法的正确性。波场分离分解技术能够加强对地震波传播规律的认识,具有重要的理论意义。A rotated staggered-grid finite-difference method is adopted in wave field modeling to calculate the first-or-der velocity and stress elastic wave equation for VTI media.The coupled P and SV waves are projected to their polarization components respectively to separate them apart.And then,the separated P and SV waves are rescaled according to their polari-zation vectors.The origin input wave-field can be recovered by summing the decomposed P and SV wave-field.Since the de-composition is performed under the rotated staggered grid,the approximation or interpolation processing to the wave-field is not needed,which improves the efficiency and accuracy of the wave field decomposition.This method is testified respectively by the comparison of the origin wave-field and the decomposed wave-fields of a homogeneous media and a complex layers media. The technique of wave-field decomposition is very meaningful in the study of wave propagation in the anisotropic media.

关 键 词：旋转交错网格 高阶有限差分 数值模拟 波场分离分解 

分 类 号：P631.4[天文地球—地质矿产勘探]