Real-time image algorithm for short-constant-aperture SAR

Piecewise uniform sampling local backprojection (PUS-LBP) algorithm is presented for short-constant-aperture SAR image formation. In the PUS-LBP algorithm subaperture images are formed based on the Cartesian coordinates, which dramatically improves the computation efficiency comparing with the original LBP. Furthermore, the piecewise uniform sampling technique is applied to the LBP in Cartesian coordinates. This technique increases the subimage sampling rate at the edges, but retains a lower sampling rate on the center. As a result, a consistent focusing performance of the whole image is achieved in an efficient way. The algorithm is validated by real data processing with an 86 percents speed boosting.