A review on time-to-depth conversion of migration section and velocity based on image ray
基于成像射线的偏移剖面和速度时深转换评述

The seismic velocity model in the depth domain is one of the most important parameters in seismic exploration and the basis to obtain precise migration sections in the depth domain. Based on image ray, we elaborate the relationship between the time-migration domain and depth domain, and define that the image point in the time-migration domain is related to the scattering point in depth domain by image ray. If the velocity varies laterally, in order to show the real subsurface structure, time-migration section and velocity both need a time-to-depth conversion. Different from time-to-depth conversion of migration sections, we need to correct both positions and values of the velocity in time-to-depth conversion of velocity. The correction factor can be expressed in several equivalent forms: matrix tensor, velocity spreading factor and geometrical spreading factor.