Resample in the first order motion compensation of real-time SAR processor

The resample problem in the first order motion compensation of real-time SAR processor is presented. The motion error model is properly established, and the simulation shows that the formation of the motion error with liner or second phase term gives rise to the image defocus and distortion. The magnitude of motion error poses changes in the range gate drift. When the motion error exceeds a range bin during synthetic time, resample should be taken into consideration; the resample inaccuracy within one bin does not have impact on azimuth focus, but the signal amplitude, so resample is necessary and important in motion compensation.