Magnetic particle imaging uses time-dependent drive fields for signal generation, which are designed to be homogeneous in order to achieve a similar image quality all over the volume of interest. In practice, the fields are not exactly homogeneous and in turn a precise knowledge of the spatial field profile is necessary when using a model-based reconstruction approach. In this work, we propose an efficient method for the measurement and a compact representation of the drive fields using a small three-axis coil sensor and solid harmonics.
