Stacking velocity analysis from rugged topography

Stacking velocity analysis is generally performed under the assumption of a flat surface. However, in mountainous regions, the presence of an undulating surface violates this assumption, necessitating static corrections for stacking velocity analysis. Accurately calculating static corrections, however, is challenging, making it difficult to completely eliminate the time shifts introduced by surface topography and restore the hyperbolic time–offset relationship of the reflection. Therefore, it is crucial to minimize the use of static corrections during time-domain stacking velocity analysis. Building on previous research, we propose a method to calculate reflection wave travel time under undulating surface conditions without the need for static correction. Under the assumption of slow lateral velocity variations, the root-mean-square velocity and two-way vertical time (\(t_{0}\)) for each shot point and receiver point are calculated using the Dix formula separately, followed by the computation of travel time from shot point and receiver point to reflection point, yielding the reflection travel time in the time domain. This time-domain reflection travel time calculation method is applied to stacking velocity analysis of mountainous data with undulating surface conditions. This method greatly improves the accuracy of travel time calculations for reflection waves, enhancing velocity estimation under complex surface conditions. Numerical experiments validate the effectiveness of the proposed approach.