We exploit the different but complementary data sensitivities of ground-penetrating radar (GPR) and electrical resistivity (ER) by applying a multiphysics, multiparameter, simultaneous 2.5D joint inversion without invoking petrophysical relationships. Our method joins full-waveform inversion (FWI) GPR with adjoint derived ER sensitivities on the same computational domain. We incorporate a stable source estimation routine into the FWI-GPR. We apply our method in a controlled alluvial aquifer using only surface-acquired data. The site exhibits a shallow groundwater boundary and unconsolidated heterogeneous alluvial deposits. We compare our recovered parameters to individual FWI-GPR and ER results, and we compare them to log measurements of capacitive conductivity and neutron-derived porosity. Our joint inversion provides a more representative depiction of subsurface structures because it incorporates multiple intrinsic parameters, and it is therefore superior to an interpretation based on log data, FWI-GPR, or ER alone.
This document was originally published in Geophysics by Society of Exploration Geophysicists. Copyright restrictions may apply. https://doi.org/10.1190/geo2021-0161.1
Domenzain, Diego; Bradford, John; and Mead, Jodi. (2022). "Joint Full-Waveform Ground-Penetrating Radar and Electrical Resistivity Inversion Applied to Field Data Acquired on the Surface". Geophysics, 87(1), K1-K17. https://doi.org/10.1190/geo2021-0161.1