Macro velocity building is important for subsequent prestack depth migration and full waveform inversion. Wave equation migration velocity analysis (WEMVA) utilizes band-limited waveform to invert the velocity in an automatic manner. Normally, inversion would be implemented by focusing the subsurface offset common image gathers(SOCIGs). We re-examine it with a different perspective and propose to view the SOCIGs and the background wavefield together as subsurface offset virtual sources(SOVS). A linear system connecting the perturbation of the position of those SOVS and velocity is derived and solved subsequently using a conjugate gradient method. Both synthetic and real dataset examples verify the correctness and effectiveness of the proposed method.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledgements: The real data shown in this study is proprietary to and provided courtesy of CGG company. We are grateful to them. The authors also thank for the resources of the supercomputing Laboratory at KAUST.