Approximating the performance of a time domain pulsed induction EMI sensor with multiple frequency domain FEM simulations for improved modelling of Arctic EMI sensing of ice thickness

<p dir="ltr">One of the key challenges with developing pulsed induction (PI) electromagnetic induction (EMI) sensors for use in the arctic is the inaccessibility of the environment, which makes in-situ testing prohibitively expensive. To mitigate this, sensor development can be streamlined through creation of a robust simulation strategy with which to optimize features such as coil turns and geometry. Building on work which previously presented a method for simulating an arctic PI sensor via a time domain finite element model (FEM), this paper presents a method for approximating a time-domain simulation with multiple frequency domain simulations. A comparison between the fast Fourier transform (FFT) of a time domain simulation, a collection of frequency domain simulations is presented. These are validated against empirical data with a PI sensor over seawater, with an air gap used as proxy for sea ice. Using the method described, a range of coils have been simulated with dimensions from 0.5 × 0.5 m up to 1.0 × 2.0 m, which demonstrates the ability of this approach to allow a comparison of sensor performance over a wider parameter space. For a parametric sweep over 10 sensor-to-seawater lift off distances, the improvement from a time domain simulation (of a 402 μs window) to a frequency domain simulation (comprising 100 discrete frequencies) represents a reduction in simulation time from 38,013 minutes to 141 minutes.</p>