Numerical Modeling and Evaluation of the Small Magnetometer in Low-Mass Experiment (SMILE)

Abstract: Fluxgate magnetometers have played a major role in space missions due to their stability, range of operation and low energy consumption. Their principle of operation is relatively simple and easy to implement, a nonlinear magnetic material is driven into saturation by an alternating excitation current inducing a voltage that is modulated by the external field intended to be measured. With the increasing use of nanosatellites the instruments and payload on board have been reduced considerably in size and weight. The Small Magnetometer in Low-Mass Experiment, SMILE, is a miniaturised triaxial fluxgate magnetometer with volume compensation incorporating efficient signal processing algorithms within a field programmable gate array (FPGA). SMILE was designed in collaboration between the Lviv Centre of Institute of Space Research in Ukraine where the sensor was developed and the Royal Institute of Technology (KTH) in Stockholm, Sweden where the electronics used to operate the instrument were designed and programmed. The characteristic dimensions of the SMILE magnetometer and geometry of its parts make impractical the task to find an analytical expression for the voltages induced in the pick-up coils to evaluate its performance. In this report, the results of numerical simulations of the SMILE magnetometer using a commercial finite element method (FEM) based software are presented. The results obtained are compared with the experimental data available and will serve as a first step to understand the behaviour of the nonlinear components that could lead to improvements of its design in a future.