Research on Fast Convolution Backprojection Algorithm for Spotlight Synthetic Aperture Radar

In this paper,one of spotlight SAR imaging algorithms,the convolution backprojection(CBP) algorithm,is studied in detail.A new fast backprojection reconstruction algorithm for spotlight-mode SAR is proposed to reduce computation load.Based on the decomposition of the image and angular downsampling,the new algorithm adopts a recursive method and thus reduces the computational cost.The choice of the parameters that affect the behavior of the algorithm,such as recursion and angular oversampling is discussed,and the effects of four different interpolation methods are simulated.The analysis of the relationship between cost and distortion is also presented.Comparison with direct CBP suggests that FCBP offers acceptable root mean square reconstruction errors with considerable speedup.