黏弹介质时空域高斯波包偏移

Time-space Gaussian packets migration in viscoelastic media

基于Katchalov提出的矢量时空域高斯束表达式,构建弹性波介质中的矢量时空域格林函数;使用Kirchhoff-Helmholtz积分解得到检波点矢量波场,并利用散度、旋度算子在矢量波场中分离出纯纵波和纯横波分量;基于衰减补偿原理,对波场进行衰减补偿,最后使用震源归一化成像条件得到PP、PS成像结果。数值实验证明了所提方法的正确性和适应性。结果表明,所提方法相比于传统的高斯束方法,成像精度近似,计算效率方面有较大优势。

Based on the vector time-space domain Gaussian beam expression proposed by Katchalov,the vector time-space domain Green s function in elastic wave media is constructed.The Kirchhoff-Helmholtz integral is applied to obtain the vector wave field of the receiver point,and the divergence and curl operators are used to separate the pure P-wave and pure S-wave components from the vector wave field.Based on the attenuation compensation principle,the wave field is adjusted and the final PP and PS imaging results are achieved using source-normalized imaging conditions.Numerical experiments confirm the correctness and adaptability of the proposed method.Compared with the traditional Gaussian beam method,the approach maintains similar imaging accuracy while offering significant improvements in computational efficiency.