A method of creating quickly an initial model in tomography inversion

Generally, tomography inversion generating a near surface model involves the creation of an initial model, and then iteratively tracing rays through the model, comparing the calculated travel time to the observed travel time, modifying the model, and repeating the process until the difference between calculated and observed times is minimized. Therefore, quality of an initial model will affect precision of inversion, velocity of convergence and number of iterations directly. In the paper, a near surface model is simulated, and then one initial model is created quickly by time-term inversion method for tomography inversion. At last, through analyzing the tomography inverting model, precision of inversion is improved, velocity of convergence is accelerated and number of iterations is decreased.