Microwave gauging with improved angular resolution

Angular resolution of a microwave level gauge may have positive impact on the robustness of the target detection. Therefore, an azimuthal scan can be performed with the aid of electronical or mechanical beam-steering methods. The present paper provides an overview and a comparison of signal-processing methods which improve the angular resolution of such measurements. For a given antenna, improvements can be achieved well beyond the limit of the half-power beam-width (HPBW) of that sensor. Among others, the performance of the Wiener filter and the Kalman filter for a motion-free channel is examined in greater detail since their application exhibits promising improvements on the angular resolution in both, simulations and measurements. In addition, the advantage of using a Kalman filter for a channel with statistical fluctuations is shown in simulations.