Mutually Constrained Inversion of Common Offset GPR Reflection and Surface Wave Dispersion Data in Layered Media

Abstract

Summary Ground penetrating radar (GPR) and seismic surface wave methods (SWMs) are widely used in near-surface surveys. For the most frequently used common offset GPR reflection data, a key requirement for proper imaging of subsurface reflectors is an accurate velocity model, especially when dipping layers are present in the subsurface. For the inversion of surface wave data in a layered system, the model parameterization is critical if a priori information is not available. Here, we presented a possible way for mutually constrained inversion of the common offset GPR reflection traveltime and surface wave dispersion data. We used the depth of interfaces to link the model parameters of GPR and the surface wave method based on structural similarity. The parameterization problem of the surface wave data inversion is mitigated by using interface constraints from GPR profile, we then inverted the layered model parameters including thickness and velocities of EM wave and shear wave simultaneously by using the alternate coupling strategy. Test on a synthetic example showed that the estimation of depth and EM velocity in GPR result is significantly improved, while, the simultaneous use of both datasets could provide a reliable parametrization for the surface wave inversion.