能量约束下的高斯射线束法地震波场正演

Seismic wave field modeling by energy controlled Gaussian beam method

高斯射线束法同时考虑波的运动学和动力学特征,并且无需两点试射追踪,因此运算速度快、精度较高。Zoeppritz方程反映了地层界面上反射波和透射波的能量。本文将高斯射线束正演与Zoeppritz方程联系起来,将高斯射线束正演得到的波场记录赋予能量信息,并利用模型对波动方程、常规射线法和本文方法的计算精度和效率进行了对比,验证了本文方法的可行性和有效性。

Gaussian beam method is an improvement of the traditional ray tracing method in seismic modeling.It simultaneously involves characteristics of both kinematics and dynamics without the trial ray tracing between two points.So it is more efficient and accuracy.However,its energy of wave field is not enough compared with wave equation methods.Zoeppritz's equations can give the conversion information and decide energy distribution about P-and S-waves when reflection and transmission occurs at layer interfaces.By combination of Zoeppritz's equations and Gaussian beam forward modeling,we realize ray beams endowed energy information and achieve a fast and efficient wave field modeling method.Several models are tested with wave equation methods,conventional ray tracing methods and our method.The results show the feasibility and effectiveness of this new method.