起伏地形下地下间断面被动源叠前逆时偏移成像

• Published in: Beijing da xue xue bao Vol. 54; no. 5; pp. 983 - 993
• Main Authors: Liang, Zuokui, Ge, Zengxi
• Format: Journal Article
• Language: Chinese
• Published: Beijing Acta Scientiarum Naturalium Universitatis Pekinenis 20.09.2018; 北京大学地球与空间科学学院地球物理学系,北京,100871
• Subjects: Nonlinear programming; Viscosity; 起伏地形; 被动源; 边界元法; 有限差分法; 逆时偏移成像
• ISSN: 0479-8023
• DOI: 10.13209/j.0479-8023.2017.110

Because the most used finite difference method to calculate wave propagation cannot handle irregular boundaries easily, a hybrid boundary element and finite difference method is proposed. Firstly, the boundary element method is used to obtain the wavefileds along a horizontal boundary which is going to be the boundary condition of the finite difference method in the next stop. Then the finite difference method is applied to obtain the wavefields under the interface. The wavefields are separated to vector P-wave and S-wave constituents, and considering the coherence of P-wave and S-wave in a conversion point, the image condition of cross-correlation between P- and S-waves is applied to obtain discontinuity image underground. Synthetic tests show the effectiveness of the proposed method.