一种快速建立层析反演初始模型的方法

A method of creating quickly an initial model in tomography inversion

建立近地表层析反演模型时,通常利用射线追踪方法来计算模型初至旅行时,再与观测的初至实际旅行时进行比较,反复修改模型直到计算值与观测值的误差达到最小。因此,初始模型建立的质量直接影响到层析反演的精度、收敛速度和迭代次数。通过模拟近地表模型,利用时间项反演方法快速建立初始模型,提高了层析反演的精度,加快了收敛速度,减少了迭代次数。

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.