Sparse array imaging for microwave gauging by compressed sensing

The reliability of microwave level gauging can be improved by radar imaging techniques. An antenna array with a large aperture must be used, in order to achieve the desired resolution. At the same time, the number of array elements is limited to only a few, which leads to ambiguities due to spatial undersampling. The ambiguities can be resolved by application of compressed sensing (CS) techniques, as this paper will demonstrate. A model of this particular problem is developed, such that CS algorithms can be applied. Statistical analyses demonstrate the robustness of the method. Finally, measurements of a frequency modulated continuous wave (FMCW) system are presented, with an array size of down to 4 elements.