An Efficient Image Reconstruction Algorithm for Maneuvering Platform SAR Integrated With Elevation Information in Hybrid Coordinate System

Because fast factorized back-projection (FFBP) algorithm is not limited by the assumption of azimuth-invariant of echo signal, it has significant advantages for maneuvering platform synthetic aperture radar (MP-SAR) imaging. Due to the curved trajectory of MP-SAR, the focusing quality of the SAR image becomes very sensitive to the terrain scene elevation, and the range and angular histories are difficult to be solved in polar coordinate system for FFBP implementation. In this letter, a new image reconstruction algorithm integrated with elevation information is proposed for MP-SAR imaging with high efficiency. The proposed algorithm is based on the hybrid coordinate system which is incorporated with elevation information in the FFBP process. In the proposed algorithm, a flexible matching region is introduced to efficiently solve the range and angular histories in FFBP recursion which can reconstruct high-quality images of terrain scene with both high accuracy and efficiency. Simulation experiments are implemented and analyzed to validate the superior performance of the proposed algorithm.