New quick-look algorithm for spaceborne synthetic aperture radar based on ECS + FIR

In the space-borne SAR quick-look processing, it can not satisfy the process precision and the process speed simultaneously with the conventional quick-look algorithms, SPECAN, RD + FIR, etc, to process the echo data which has large range migration. To solve this problem, this paper presents a quick look algorithm: ECS + FIR (Extended Chirp Scaling and FIR filter) algorithm, which is based on the equivalent slant range model. The computation amount of this algorithm will not change with the increase of the range migration, so it is quite suitable to process the space-borne SAR echo data with large range migrations. In addition, this algorithm uses sub-aperture data in the azimuth processing instead of the FIR filter in azimuth, which reduces the computing amount. The principle and flow chart of the algorithm are discussed in details, and a comparison between the ECS + FIR and other quick look algorithms is made. Several simulation study results are given to demonstrate the feasibility of the algorithm.