Image reconstruction in seismic and medical tomography

Abstract

Tomography has been used for more than 40 yr in medical science and its success is well known. One of the most important reasons for the success of medical tomography compared to seismic tomography is the data-acquisition geometry. A data-acquisition geometry similar to the one used in medical tomography was designed and tested with synthetic geological models. Geophysical-type data-acquisition geometries were also applied to the geological models, and the resulting images were compared to the medical images. The reconstructed image obtained in the medical case resembled the synthetic geological model and had higher resolution than the geophysical image. Secondary attention is drawn to the determination of the differences between the low- and high-velocity zones in the final image reconstruction of the tomographic inversion process. Therefore, the step-like high- and low-velocity embedded layer models were tested with different spreading systems. The geological models were also tested with one-dimensional (1-D) initial velocity models to understand the effect of the initial velocity model on the final image reconstruction. In the high-velocity layer case, the tomographic process is quite successful in image reconstruction, but cannot achieve the same success In the low-velocity layer case.