Abstract: In the system of Displaced Phase Centre Multiple Azimuth Beams (DPCMAB) of spaceborne SAR，the transmitter blinding and nadir echo eclipsing events can lead to nonuniform azimuth sampling that results in the appearance of unexpected peaks on the both sides of mainlobe of azimuth impulse response. In this paper，the Spectral-Fit method and the reconstruction in time domain method are adopted to eliminate the effect due to azimuth nonuniform sampling with the quality of image being unaffected. Contrasting the number of arithmetic operations of the above two methods, it is shown that the reconstruction in time domain method is superior to the Spectral-Fit method.