衍射地震CT技术的数值研究

本文首先解决了声波方程的非Born近似的正演计算问题,从而获得理论上不带近似的正演数据;然后,推导了井间（CBP）、垂直地震剖面（VSP）和地面反射（SRP）三种不同的数据采集方式下的衍射CT的重建公式;利用这些重建算法和正演数据,系统地研究了影响到地球物理CT成象质量的三种因素,即:（1）数据采集方式,（2）异常程度和（3）成象区域的尺寸,对重建图象的影响;并比较了衍射地震CT和射线地震CT的成象质量。

A COMPUTER SIMULATION STUDY ON THE DIFFRACTION SEISMIC TOMOGRAPHY

Based upon the existed problems in diffraction seismic tomography,in this paper,we firstly have solved the forward calculation of the two dimensional wave equation using non-Born or Rytov approximation method; then we have derived the diffraction tomography reconstruction formulas under three independent data acquisition configurations such as the cross boreholes profiling (CBP),the vertical seismic profiling (VSP) and the surface reflection profiling (SRP).Using the reconstruction algorithms and data calculated,we have systematically studied the three factors that can affect the reconstructed images,namely: (1) data acquisition configuration,(2) the dimension and (3) the abnormity of the abnormal structures.We also have compared the diffraction tomography with the travel-time tomography under weak inhomogenety.