Inversion velocity model, method for establishing the same and method for acquiring images of underground structure

摘要

The present application relates to geophysical survey, particularly provides an inversion velocity model, a method for establishing the same and a method for acquiring images of underground structure. The method for establishing inversion velocity model comprises: converting observation seismic records into first intermediary data which contains data with frequency no higher than a first predetermined frequency; calculating synthetic seismic records based on a set initial velocity model and converting the synthetic seismic records into second intermediary data which also contains data with frequency no higher than the first predetermined frequency; establishing an objective function based on the first intermediary data and the second intermediary data; calculating a velocity gradient of seismic wave based on the objective function; calculating a iteration step of the velocity gradient; determining the inversion velocity model based on the velocity gradient and the iteration step.