A fast algorithm for common-offset Gaussian beam migration

作者：Gao Zheng-Hui^*; Sun Jian-Guo; Sun Zhang-Qing; Sun Xu; Shi Xiu-Lin; Liu Zhi-Qiang

来源：Acta Geophysica Sinica, 2017, 60(3): 1118-1131.

DOI：10.6038/cjg20170323

• Common-offset
• Gaussian beam migration
• Fast algorithm
• Interpolation method

Compared with the common-shot Gaussian beam migration, the common-offset Gaussian beam migration has the advantage in direct extraction of offset-domain common-image gathers. In the past, the common-offset Gaussian beam migration adopted the steepest descent method to reduce the dimension of the integrals at the cost of losing precision and to increase computation efficiency. However, the migration formula simplified by the steepest descent method is still in the frequency domain, and it has to be evaluated at each frequency. To solve this problem, we develop a fast algorithm to avoid adopting the steepest descent method. We test the effects of different interpolation methods on the imaging accuracy and the computational efficiency of the fast algorithm through analyzing the migration procedures on a horizontally layered velocity model and the imaging results of the Marmousi velocity model. We suggest to adopt the bicubic convolution interpolation method. The superiority of this fast algorithm on the imaging accuracy and the computational efficiency compared with the steepest descent method is validated with the Marmousi velocity model. Furthermore, we apply this fast algorithm using the bicubic convolution interpolation to the Sigsbee2A model and obtain clear subsalt image.

• 出版日期2017-3
• 单位吉林大学