A fast decimation-in-image back-projection algorithm for SAR

Fast back-projection algorithms are required for new modalities of SAR, such as UWB SAR. In this paper we propose a novel algorithm which we call the fast decimation-in-image back-projection algorithm due to its relation to decimation-in-time FFT algorithms. It is the natural dual of existing fast back-projection algorithms which are related to decimation-in-frequency FFT algorithms. The proposed algorithm provides similar speed up to existing algorithms, however, it has additional advantages. The advantages relate to the way in which the algorithm manifests errors. The size and nature of the errors introduced in the proposed algorithm are more desirable than that of existing algorithms.