Abstract:Traveltime tomography always uses first arrival traveltime to invert near surface structures of the earth. Conventional ray-based tomography method is limited by low efficiency and poor stability in complex structures. In this paper, we use the fast sweeping method (FSM) to get the first arrival traveltime stably and efficiently based on the finite differential operator of the Eikonal equation. Then, the adjoint state method is applied to calculate the gradient of the misfit function. The combination makes the traveltime tomography more efficient. Both this method and the conventional ray-based tomography are applied to theoretical models and field data. Inverted results indicate that the adjoint state method can retrieve velocity structure with similar accuracy as conventional ray-based tomography, while the cost of computation is much less.
谢春, 刘玉柱, 董良国, 杨积忠. 伴随状态法初至波走时层析[J]. 石油地球物理勘探, 2014, 49(5): 877-883.
Xie Chun, Liu Yuzhu, Dong Liangguo, Yang Jizhong. First arrival traveltime tomography based on the adjoint state method. OGP, 2014, 49(5): 877-883.