The Processing Workflow of Semi-Airborne Transient Electromagnetic Data Using Geological Modeling and Three-Dimensional Numerical Simulation – A Case History in Yunnan, China

To overcome the limitations including the topography in survey area and the complex geometry of the target on conventional transient electromagnetic method (TEM) interpretation, we extend in this paper a workflow for processing semi-airborne TEM data. Based on the digital topography data, geologic sections and well logs, a 3D geologic model was built for numerical simulation. After mapping the geologic model to resistivity mesh, a mimetic finite volume with Krylov subspace method was used for calculating the influence coefficient of topography. This processing workflow was applied on a semi-airborne TEM survey for determining the thickness of cover layer on a hillside in Yunnan, China. The thickness of the cover layer inferred from the processed TEM data is consistent with the local geological sections. This workflow can not only process measured data, but also perform numerical simulation on the target area with complex topography and stratum structure.