Compressive sensing algorithm for downward-looking sparse array 3-D SAR imaging

Sparse array can avoid unwanted grating lobes and take full advantage of the wingspan space, which is widely applied in downward-looking 3-D SAR. In the paper, a 3D imaging strategy based on compressive sensing theory is proposed for downward-looking sparse array SAR imaging, which can improve the performance in cross-track direction. T/R sparse array and MIMO sparse array, as the representative distributions of the sparse array, are discussed in the paper. Compared with T/R sparse array, MIMO sparse array can achieve high imaging performance with less real antenna elements. Simulation results indicate that the proposed algorithm can provide high quality imagery compared to the conventional method.