地震包络反演对局部极小值的抑制特性

Local minima reduction of seismic envelope inversion

为了实现包络反演,需要通过一种非线性运算来提取信号包络.这种非线性的包络提取过程可以将信号包络中所包含的对介质扰动的大尺度响应从原始地震信号中分离出来,从而抑制反演中的局部极小值,能够在缺乏低频信息的情况下,为全波形反演提供一个良好的初始模型.本文研究包络反演对局部极小值的抑制作用,并通过目标函数形态的对比来展现这一特性.对Marmousi速度模型和Overthrust速度模型做了反演,证明了该方法的有效性.

In order to perform envelope inversion, we need to first extract the envelope using the nonlinear operation. This nonlinear envelope extraction can separate the large-scale response coded in the envelope from the waveform data, which can reduce the local minima in the misfit function and provide a good initial model for full waveform inversion without the low-frequency information. This paper shows the reduction of local minima using this method and compares the misfit configurations. The inversion on the Marmousi model and the Overthrust model attest to the validity of this method.