Improving The Computational Efficiency of 3-D Modeling of Induced Polarization in Airborne Time-Domain Electromagnetic Problems

Summary The article proposes mathematical models for calculating induced polarization (IP) when solving 3-D airborne time-domain electromagnetic problems. The proposed approaches are optimized directly for solving “multisource” problems for further application in data processing systems. For constructing finite element approximation, we use optimized non-conforming hexahedral meshes allowing to drastically reduce the number of degrees of freedom while keeping the required solution accuracy. In addition, to provide calculations with a large number of positions of the transmitter-receiver set, the space-time grouping of subtasks corresponding to different positions of the airborne system and parallelization were used. We present a comparison of the developed computational schemes that perform calculations both directly in the time domain and in the frequency domain, as well as a comparison with the results of other authors. It is shown that the solutions obtained using different approaches are in good agreement with each other. The computational costs required for calculating the electromagnetic field taking into account the IP effects in a complex 3-D medium with topography are about 10 s per position. This will make it possible to use this approach in the future in systems for processing airborne data.