We analize the reason of periodic bright and shadow stripe noise generated in burst mode SAR

when the full aperture imaging algorithm is used.A simple but efficient one-dimensional frequency domain filtering method is proposed along with the flow chart of improved Range Doppler imaging algorithm including this operation.We discuss the nonperiodic abnormal stripe noise due to the spaceborne SAR system itself

and present an area filtering method in two-dimensional frequency domain.The validities of the algorithms in the paper are proved by processing actual spaceborne SAR data.