improving motion compensation in synthetic aperture radar using approximated differential error

due to the tilt of the platform carrying the synthetic aperture radar(sar), the image formation algorithms(like rda) can not yield to good quality images from the ground. therefore, it is convenient to use a two-step approach for motion compensation in image formation algorithms. in this paper, using an approximated linear model for the motion error and the impact of range compression step of rda on the differential error, it is shown that the required phase is changed in the differential compensation, and so its considering can yield to more qualified images. then the proposed method accompanying with an intermediate stage of compensation is evaluated for more reform of range migration. finally the simulation results are presented to show that the proposed method has better performance compared with the conventional two-step procedure.