We present a dispersion-inversion method which inverts for the P-velocity model from guided waves propagating in wave guides of arbitrary geometry. Its misfit function is the squared summation of differences between the predicted and observed dispersion curves of guided P waves, and the inverted result is a high-resolution estimate of the near-surface P-velocity model. We denote this procedure as wave-equation dispersion inversion of guided P waves (WDG), which is valid for near-surface waveguides with irregular layers and does not require a high-frequency approximation. It is more robust than full waveform inversion and can sometimes provide velocity models with higher resolution than wave-equation traveltime tomography. Both the synthetic-data and field data results demonstrate that WDG for guided P waves can accurately invert for complex P-velocity models at the near surface of the Earth.
Bibliographical noteKAUST Repository Item: Exported on 2020-10-01
Acknowledged KAUST grant number(s): OCRF-2014-CRG3-2300
Acknowledgements: We thank the financial support from the sponsors of the Consortium of Subsurface Imaging and Fluid Modelling (CSIM) and the supercomputing center at KAUST for computational resources. We also thank the KAUST, which provided the funding by the CRG grant OCRF-2014-CRG3-2300, National Natural Science Foundation of China (NSFC) (41504083), and China Postdoctoral Science Foundation (2016T902503, 2015M571366). All data used in this paper are freely available at CSIM group lab (https://csim.kaust.edu.sa/files/FieldData/Qademah_2014/QademahFault.htm).